A trajectory planning method for an autonomous vehicle includes a lateral displacement planner that plans a preliminary traveling trajectory for an autonomous driving vehicle based on perceptual data, positioning data, and map information, where the preliminary traveling trajectory includes N road points, and each road point includes coordinate information of the road point and allowable lateral error information of the road point. A longitudinal speed planner inherits all or some of the N road points output by the lateral displacement planner and determines speed information of n road points based on traffic road condition information and the perception data to obtain a target traveling trajectory. The speed information is a drivable speed of the autonomous driving vehicle at each of the n road points. The target traveling trajectory includes the n road points, each of the n road points including the drivable speed of the autonomous driving vehicle at the road point.