Q: Why my Apple ID can buy anything in the apple store Nuys can not buy in the game?

Hello Guiqi Zhang,

Thank you for the details of the issue you are experiencing with the iTunes Store on your iPad.  For the issue you are experiencing, I recommend signing out and back into the iTunes Store on your iPad:

Changing your Apple ID account

Tap Settings > iTunes & App Stores, then tap the Apple ID signed in.

Sign out of the current Apple ID account and then sign in with another account or create a new Apple ID.

The last step states to sign in with another account, but for the situation you described, I recommend just signing in with your same Apple ID.

You can find the full article here:

iOS: Changing the signed-in iTunes Store Apple ID account

http://support.apple.com/kb/HT1311

If the issue persists after signing out and back in, I recommend following the iOS steps in the section titled "Troubleshoot issues on an iPhone, iPad, or iPod touch" in the following article (you can skip any steps you have already taken):

Can't connect to the iTunes Store

http://support.apple.com/kb/TS1368

Thank you for using Apple Support Communities.

Best,

Sheila M.