With the rapid development of safety science, traditional accident management has become risk management. Based on the analysis of cases, this paper puts forward the method of establishing a risk assessment model, which can effectively reduce the risk of navigation, and constructs the relative risk model based on multi-factors and the Bayesian Risk consequence model under stochastic information. Before a ship goes to complex waters, it can quantitatively analyze the factors such as accident frequency, risk degree and accident consequence, and construct a risk assessment model for navigation accidents, to effectively reduce the probability of navigation accidents.