Got other language in imessage notification

Unfortunately, I don't know what you mean by Change iMessage Notification since iMessage and messages app follow the language set on the iPhone. You may try these steps:

To change the Language of your iPhone,

Go to Settings -> General -> Languages -> iPhone Language.

To change the region you are in,

Go to Settings -> General -> Languages -> iPhone Region

To change the language for a specific app,

Go to Settings -> Scroll down to the App's Name, -> Language.

Not all apps support different language than your system language

so to change language of specific app (you cant change language only for notification, you need to change language for whole app ), go to settings, then scroll to the app that you need to change language for , then when you click on the app , you will see at bottom "language" , change it to what ever you want, (note: not all apps have this feature it depends on developer)

I just saw the picture.

Do you live in China Mainland/Taiwan/Or is using a Phone Number from China Mainland/Hong Kong/Makau?