直接上代码：

using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using UnityEngine.UI;
using TMPro;

public class ExchangeFont : EditorWindow
{
    [MenuItem("Tools/UI/更换字体")]
    public static void Open()
    {
        EditorWindow.GetWindow(typeof(ExchangeFont), true);
    }

    static bool isSelectOldFont = false;
    static Font oldTextFont;
    static TMP_FontAsset oldTextMeshProFont;

    static Font selectTextFont;
    static TMP_FontAsset selectTextMeshProFont;


    static bool isChangeLineSpacing = false;

    private static float NewLineSpacing = 1;

    private static string selectedFolderPath;


    private void OnGUI()
    {
        GUILayout.Space(10);

        isSelectOldFont = EditorGUILayout.Toggle("是否需要选中被替换的字体：", isSelectOldFont);

        EditorGUI.BeginDisabledGroup(!isSelectOldFont);
        oldTextFont = (Font)EditorGUILayout.ObjectField("选择被更换的Text字体", oldTextFont, typeof(Font), true);
        GUILayout.Space(5);
        oldTextMeshProFont = (TMP_FontAsset)EditorGUILayout.ObjectField("选择被更换的TextMesh字体", oldTextMeshProFont,
            typeof(TMP_FontAsset), true);
        GUILayout.Space(5);
        EditorGUI.EndDisabledGroup();


        GUILayout.Space(5);
        isChangeLineSpacing = EditorGUILayout.Toggle("是否修改行间距：", isChangeLineSpacing);

        EditorGUI.BeginDisabledGroup(!isChangeLineSpacing);

        NewLineSpacing = EditorGUILayout.FloatField("新行间距", NewLineSpacing);

        EditorGUI.EndDisabledGroup();


        GUILayout.Space(10);
        selectTextFont = (Font)EditorGUILayout.ObjectField("选择新的Text字体", selectTextFont, typeof(Font), true,
            GUILayout.MinWidth(100));
        GUILayout.Space(5);
        selectTextMeshProFont = (TMP_FontAsset)EditorGUILayout.ObjectField("选择新的TextMesh字体", selectTextMeshProFont,
            typeof(TMP_FontAsset), true, GUILayout.MinWidth(100));
        GUILayout.Space(5);

        GUILayout.Space(20);
        if (GUILayout.Button("更换选中的预制体", GUILayout.MaxHeight(30)))
        {
            if (selectTextMeshProFont == null && selectTextFont == null)
            {
                Debug.LogError("请选择字体！");
                return;
            }

            if (Selection.gameObjects == null && Selection.gameObjects.Length < 1)
            {
                Debug.LogError("未选中预制体！");
                return;
            }

            var selectedObjects = new List<GameObject>();

            selectedObjects.AddRange(Selection.gameObjects);
            ChangeFont(selectedObjects);
        }


        GUILayout.Space(20);

        GUILayout.BeginHorizontal();

        EditorGUILayout.TextField("选择的修改路径：", selectedFolderPath);

        if (GUILayout.Button("选中路径", GUILayout.MaxWidth(80)))
        {
            if (Selection.assetGUIDs.Length > 0)
            {
                string guid = Selection.assetGUIDs[0];
                selectedFolderPath = AssetDatabase.GUIDToAssetPath(guid);
            }
            else
            {
                Debug.LogError("没有选中文件！");
            }
        }

        if (GUILayout.Button("选择路径", GUILayout.MaxWidth(80)))
        {
            var paht = EditorUtility.OpenFolderPanel("选择路径", Application.dataPath, "");
            selectedFolderPath = paht.Replace(Application.dataPath, "Assets");
        }

        GUILayout.EndHorizontal();

        GUILayout.Space(5);
        if (GUILayout.Button("更换选中路径下所有的预制体", GUILayout.MaxHeight(30)))
        {
            if (selectTextMeshProFont == null && selectTextFont == null)
            {
                Debug.LogError("请选择字体！");
                return;
            }

            ChangeSelectFloud();
        }
    }

    public static void ChangeSelectFloud()
    {
        var selectedObjects = new List<GameObject>();

        if (!string.IsNullOrEmpty(selectedFolderPath))
        {
            string[] prefabGUIDs = AssetDatabase.FindAssets("t:Prefab", new string[] { selectedFolderPath });
            foreach (string guid in prefabGUIDs)
            {
                string prefabPath = AssetDatabase.GUIDToAssetPath(guid);
                GameObject prefab = AssetDatabase.LoadAssetAtPath<GameObject>(prefabPath);

                if (prefab != null)
                {
                    selectedObjects.Add(prefab);
                }
            }
        }

        ChangeFont(selectedObjects);
    }


    public static void ChangeFont(List<GameObject> targetkLists)
    {
        if (targetkLists == null || targetkLists.Count < 1)
        {
            Debug.LogError("可修改预制体数量为0！");
            return;
        }

        int maxCount = targetkLists.Count;

        int curCount = 0;


        for (int i = 0; i < targetkLists.Count; i++)
        {
            EditorUtility.DisplayProgressBar("开始替换字体", "Show a progress bar for the given seconds",
                curCount / maxCount);

            var Texts = targetkLists[i].GetComponentsInChildren<Text>(true);
            ChangeText(Texts);

            var tmpTexts = targetkLists[i].GetComponentsInChildren<TMP_Text>(true);
            ChangeTextMeshPro(tmpTexts);

            var tmpUGUIs = targetkLists[i].GetComponentsInChildren<TextMeshProUGUI>(true);

            curCount++;
        }

        EditorUtility.ClearProgressBar();

        AssetDatabase.SaveAssets();
    }


    static int ChangeText(Text[] lists)
    {
        int count = 0;
        foreach (Text text in lists)
        {
            Undo.RecordObject(text, text.gameObject.name);
            if (isSelectOldFont)
            {
                if (text.font != null && text.font != oldTextFont)
                {
                    continue;
                }
            }

            if (selectTextFont != null)
                text.font = selectTextFont;
            if (isChangeLineSpacing)
                text.lineSpacing = NewLineSpacing;
            EditorUtility.SetDirty(text);
            count++;
        }

        return count;
        ;
    }


    static int ChangeTextMeshPro(TMP_Text[] lists)
    {
        int count = 0;
        foreach (TMP_Text text in lists)
        {
            Undo.RecordObject(text, text.gameObject.name);

            if (isSelectOldFont)
            {
                if (text.font != null && text.font != oldTextMeshProFont)
                {
                    continue;
                }
            }

            if (selectTextMeshProFont != null)
                text.font = selectTextMeshProFont;
            if (isChangeLineSpacing)
                text.lineSpacing = NewLineSpacing;
            EditorUtility.SetDirty(text);
            count++;
        }

        return count;
        ;
    }

    static void ChangeTextMeshProUGUI(TextMeshProUGUI[] lists)
    {
        foreach (var tmp in lists)
        {
            tmp.isRightToLeftText = true;
        }
    }
}