My state bank of india global debit card in China show "transaction is not permitted to the user".

Generally, there should be three major reasons:
1. the transaction value exceeds the limit; 2. the card is in abnormal condition; 3. the bank balance is not enough for this transaction.
If it is the second condition, it is advised you go to the bank counter to consult. As I know, State Bank of India has 2 branches in PRC. One is in Shanghai and the other is set in Tianjin. If you are staying in one of the cities, it should be very convenient to solve the problem. Or, you may need to call the bank to see how to fix it.