C2C trading platform for credit has been the focus of attention, many articles have examined the issue from the theory, and analyze the causes, and there are some better proposals. This article uses the swarm simulation platform to build multi-agent based simulation model to simulate the trading process of C2C market. And I proposed a credit model which were applied to simulate the trading process, come to conclusions: punish betrayal acts only is the accessory for market credit mechanism, but making fraudulent transactions make market total profit increased according to the perspective of pure interest; the method of history credit discount could reduce times of fraudulent transactions, however, the total receipts on the market have a negative impact, a good conversion rate must be controlled, so as to ensure that the market boom, as far as possible from the perspective of the credit mechanism to reduce the production of fraudulent transactions.
