[…] hoped that you can achieve the simplified Chinese the friendly support,

Slowly I begin to understand. You want a Chinese version.
I’m afraid, you will have to find someone who knows English well enough to do the job.
In the folder [[color=#00f]lang[/color]] there’s a file [[color=#00f]english.lang[/color]] → make a copy → save as [[color=#00f]chinese.lang[/color]].
Now open [[color=#00f]chinese.lang[/color]]. In the file you will find the named variables of the forum (the menus, buttons, messages,…), an equal sign ‘=’, and the text, which will be displayed in the forum.
Example (line 54):
search_default_value =      Search


• Change language settings from English to Chinese (adding one line for big5 which supports Traditional Chinese. If big5 is not available on the server, utf8-settings for Simplified Chinese will be used):
  language =                  zh
locale =                    zh
locale =                    zh_ZH.big5
locale =                    zh_ZH.utf8
locale =                    zho
  
• Translate all text at the right side (after ‘=’) into Chinese.
  Example (line 54) translated:
  search_default_value =      搜寻
  
• Leave everything in square brackets (like [name]) unchanged.
  Example (line 192):
  rss_reply_by =              由[name], 回应于[time]:
  
• Run [color=#00f]install.php[/color], you will be asked for the Language → Chinese

After you have installed the forum, check the translations. If you don’t like some words, change the line in [[color=#00f]chinese.php[/color]], upload the file to the server and refresh your browser. You may change everything after the installation, but before you have to have at least a simple translation. Maybe Google-Translate helps.

Good luck!

--
Edit: You don’t have to re-invent the wheel.
Search the net for the exact term ‘powered by my little forum’, and you get these results:

• Simplified Chinese (2 Byte utf8)
  
• Traditional Chinese (4 Byte utf8, big5)

Some of these forums are quite big, for example this one (almost 200,000 posts, version 1.7). Others are already version 2, for example this one (small, but beta 26 with accessible language files).
Contact the webmasters of these forums if you need help with the Chinese modifications.