http://www.cnblogs.com/zhangdongsheng/p/3886974.html

原方出处：http://stackoverflow.com/questions/7256049/notepad-converting-ansi-encoded-file-to-utf-8

Here some simple steps to convert multiple files via Notepad++ without messing up with special characters (for ex. diacritical marks).

1. Run Notepad++ and then open menu Plugins->Plugin Manager->Show Plugin Manager
2. Install Python Script. When plugin is installed, restart the application.
3. Choose menu Plugins->Python Script->New script.
4. Choose its name, and then past the following code:

convertToUTF8.py

import os;
import sys;
filePathSrc="C:\\Users\\" # Path to the folder with files to convert
for root, dirs, files in os.walk(filePathSrc):
    for fn in files: 
        if fn[-4:] == '.xml': # Specify type of the files
            notepad.open(root + "\\" + fn)      
            notepad.runMenuCommand("Encoding", "Convert to UTF-8")
            notepad.save()
            notepad.close()

After all, run the script

如果要转化为ANSI 就把插件代码改为下面

import os;
import sys;
filePathSrc="C:\\Program Files\\Zend\\Apache2\\htdocs\\webservice\\" # Path to the folder with files to convert
for root, dirs, files in os.walk(filePathSrc):
    for fn in files: 
        if fn[-4:] == '.php': # Specify type of the files
            notepad.open(root + "\\" + fn)      
            notepad.runMenuCommand("Encoding", "Convert to ANSI")
            notepad.save()
            notepad.close()

editplus全部打开之后（打开为何种编码不重要），选文档(Document)菜单——文件编码(File encoding)——批量转换编码(File encoding multiple)，选中全部文件后转码，然后再全部保存。
http://linji.cn/1458.html
http://blog.sina.com.cn/s/blog_8db762e60101pk42.html