Abstract: In order to study the transmission mechanism of credit risk in economic network, considered the heterogeneity between enterprises and the scale-free characteristics of the underlying network, a credit risk transmission model is proposed. According to the mean field theory, this paper analyzes the dynamic process, further calculates the basic reproductive rate and equilibrium point, and demonstrates the relationship between the continuity of the transmission process and the basic reproductive rate. Then, in the simulation experiment, the risk transmission process without intervention, with rescue strategy and immune strategy was simulated, and the sensitivity of each parameter was analyzed. Through theoretical derivation and simulation experiments, it can be concluded that when the basic reproductive rate is less than 1, and the market gradually breaks away from the credit risk and returns to normal, and all enterprises get through the credit crisis; when the basic reproductive rate is greater than 1, credit risk will continue to spread in the economic network and continue to affect economic security. The derivation and experiment of the model provide a theoretical basis for the study of the spread of credit risk.