Abstract: To investigate the dynamic performance of long-span truss fiber reinforced polymer（FRP） bridge after repairing completion, the 92-meter-span FRP truss bridge model was established based on guide girder pushing. The vehicle-bridge coupling algorithm of long-span composite truss bridge was compiled to analyze the effects of speed, vehicle weight and road surface roughness on the mid-span vertical displacement, vertical acceleration and key member stress of the FRP truss bridge. The results show that the more uneven the road surface is, the greater the impact of the vehicle on the bridge structure is. The vertical displacement is more affected by the road surface level than that by the member stress. In the speed range from 20 km/h to 50 km/h, the impact coefficient is less affected by the speed change. When the vehicle speed exceeds 50 km/h, the influence of speed change on the impact coefficient is gradually increased. The peak curve of vehicle mass to bridge dynamic response shows linear increasing trend. When the vehicle mass is 2.80×10~4 kg with vehicle speed of 30 km/h, the maximum mid-span vertical displacement is 167 mm, which does not exceed the military emergency bridge displacement limit（L/120）, indicating that the bridge design can meet the emergency traffic requirements.