Although the goal of the universal health care in China has been realized primarily，but there is faced with a significant problem of medical insurance is that how to redeploy the various resources and exert each advantages to realize the aim of government regulation separating from management，to improve the usage efficiency of medical insurance fund. Based on PPP mode，introducing the market mechanism and encouraging the commercial insurance companies to take part in the medical security system become a feasible way. This paper takes the Urban and Rural Residents Critical Illness Insurance as an example，combining the practice of the different regions，to put forward two participation modes：insurance contract mode and entrusted management mode. Through the comparative analysis of the two modes，this paper raises the policy suggestions to provide reference for local government.