With the rapid development of economy and people’s material level，society faces a rising demand on passenger ships，especially on the international cruise. Meanwhile，the international and domestic passenger ship sinking accidents，which occur frequently in recent years，have sounded the security alarm to the relevant regulators. This paper uses AHP to take risk analysis on ferry sinking accident and establish risk evaluation model for passenger safety and reliability. Prior to using the analytic hierarchy process，this paper uses accident tree method to divide various factors that may cause a passenger ship sank. These factors mainly come from the human factor，ship factors，navigation environment factors and management factors in order to improve the scientific，validity and accuracy of the analytic hierarchy process. Finally，this paper takes 4·16 Sewol wreck accident as the example and uses a risk assessment model for the risk analysis，and concludes what measures need to be taken to prevent this kind of accident.