Does it support Chinese language?

Yes for sure

https://quickbooks.intuit.com/learn-support/global/account-management/change-language-in-quickbooks-...

Hello there, @tomchen506. Let me help you by providing an answer to your question about languages in QuickBooks Online.

The good news is that QBO International versions can modify language settings. Thus, the Chinese language is supported. You can follow the steps below on how to change it: 

1. Go to the Gear icon and select Accounts and Settings.
   
   
   
2. From the Advanced section, go to Language.
3. Click the pencil icon to edit and choose the desired language from the drop-down.
4. Hit Save then Done to save the changes.
   
   
   

Alternatively, you can also alter it from the browser settings. Here's how: 

1. From the upper-right of your browser, click the vertical ellipsis ⋮.
2. Go to Settings, then choose a language.
3. Click Add, and select the vertical ellipsis ⋮ beside the language.
4. Tick the Display Google Chrome in this language checkbox once done.
   
   

For other browsers, check this website to learn how to update it: Microsoft Forms.

If you want to manage your future invoices in a different dialect: Send your invoices in a different language in QuickBooks Online.

I appreciate your time reaching out to the Community for assistance. If you need more help managing your company settings, you can add a comment below. I'm always here to help.