In order to evaluate the collision prevention level of existing bridges and guide the setting of collision prevention measures, to reduce the risk probability of ship-bridge collision accidents. This paper is based on Yayao Bridge, the bridge pier stress model is established by Midas finite element software, and the bearing capacity of the bridge pier is calculated based on the theory of concrete strength failure. The ship collision force is calculated by ship collision force formula, and bridge collapse probability is calculated according to Aashto code. The calculation results show that the navigation hole No. 9 and No. 10 piers of Yayao Bridge are of low risk. This method can provide a basis for the design of other bridges and safe navigation of ships.