The invention discloses a transaction settlement system which comprises a business system, a transaction system, a payment system, a charging system, a message system and an accounting system. The transaction system comprises a transaction engine module, a data persistence module, a process engine module, a rule engine module, a fund processing module, a product account access module, a charging access module, a merchant notification module and a unified event module, and the payment system comprises a payment service module, a payment instruction module, a clearing service module, a clearing instruction module and a bank transaction module. The payment service module comprises a recharge protocol module, a cash withdrawal protocol module, a recharge and withdrawal protocol module and an internal transfer protocol module; the clearing service module comprises a channel management module, a task scheduling module, a file processing module and a real-time processing module; the real-time processing module comprises an online bank access module, a cartoon access module, a bank-enterprise direct connection module and an other bank access mode module, and the accounting system comprises an accounting system, a message system and a bank flow registration system.