Considering the flexible frame, a rigidflexible coupled model for threeaxle heavyduty truck is built. By comparing with the rigid vehicle model, the validity of the rigidflexible coupled vehicle model is verified. Three models of continuous speed bumps are established based on actual requirements. Taking the vertical acceleration and the vertical tire force as the evaluation index, the effects of vehicle speed, the height and width of continuous speed bumps on vehicle ride comfort are analyzed. Research results show that the height of speed bumps is proportional to vehicle body vertical acceleration and vertical tire force, whereas the width of speed bumps is inversely proportional to vehicle body vertical acceleration and vertical tire force. The speed bumps with a width of 600 mm and a height of 8 mm show a good effect of speed limit at 60 km/h, and ensure the vehicle ride comfort.