The purpose of this paper is to reveal the interactive acceleration mechanism among the real estate market, the credit market and the real economy. By putting credit risk into the general analysis framework of business cycle, the mechanism of the credit risk on the macroeconomic cycle is studied by establishing a dynamic stochastic general equilibrium model. The study found that, compared with the traditional model, the credit risk is added to make the degree of cyclical fluctuations significantly strengthened. Credit risk has amplification effect on the period fluctuation. Compared to the TFP shock, macroeconomic cycle fluctuations are more affected by the house prices shock. The model can better fit into the actual data, reflecting greater volatility and persistence of the real economy.