After returning to China for two years, I didn't pay the telephone bill in Britain, resulting in two years' arrears. Will I refuse the visa for this reason?

It is very likely that there is a record of dishonesty in Britain for this reason. If the telecommunications company informs the Home Office, the Home Office will record it and refuse to sign your re-visa application. I suggest you contact BT as soon as possible to make up the phone bill you owe, and then apply for a British visa after paying the money.