As a result of government's macroeconomic regulation, some regions of China have suffering financial disturbance,which makes some small enterprises close down because of capital chain rupture.The guarantee industry is an part of the construction of social credit system, and its survival and development are a very serious challenge now.Medium-sized enterprise security crisis which happened over the past two years in Zhejiang province is overall analyzed in this paper.This paper digs out its internal factors which mainly reflect in two aspects,and analyzes two primary causes why security crisis happens by using mathematical model.And it puts forward corresponding measures to solve the credit risks in order to provide feasible suggestions for ensuring the safety guarantee.