A typical large continuous beam bridge with span arrangement（55 + 4×90+55） m in a highway was selected as the engineering background

dynamic analysis model of bridge was established based on finite element software

at the same time the dynamic characteristics were also calculated. Seismic response of bridge structure under two levels of earthquake

exceeding probability of 63% in 100 years and exceeding probability of 2. 5% in 50 years

was studied based on the response spectrum method and time history analysis method. According to bending momentcurvature curve of pier checking section

the seismic performance of the bridge structure was evaluated. The analysis results show that the bridge is in elastic state under the E1 and E2 probability earthquake

and satisfies the design goal of elastic design of the lower structure. Research results of this article can provide reference for the similar bridge seismic design.