The invention provides a payment control method and a system based on credit data. The method includes that a third-party payment platform receives payment requests sent by a merchant server; whether the state of a merchant is normal is judged, if the state is normal, a user is prompted to input credit account information, whether the state of a credit account is normal and an available amount is larger than or equal to an order amount are judged, if the state is normal and the available amount is larger than or equal to an order amount, deduction treatment of the credit account, collection treatment of the merchant and calculation treatment of transaction procedure fees are performed. The third-party payment platform provides a credit account with a certain amount and a payment day for users at different merchants respectively according to parameter values of users, in an available amount, users can complete safe network transaction in the condition that actual cash payment is produced without banks, and accordingly, the capital turnover efficiency is accelerated, and fund yields of industry chains are improved.