There has been a long-term imbalance between the rural economy development and the agriculture loans in China. Under this information dissymmetry situation, credit rationing lead by the adverse selection and moral hazard makes it more serious. Focusing on the dual credit structure and the catastrophe theory, this article analyses the credit rationing problem theoretically and empirically. Furthermore, the empirical study indicated that the participation of non-formal credit institution can abate the credit rationing of agricultural enterprise effectively in the competitive loan market.