Abstract: In order to steer the snake robot along the desired path guided by path edges, a path edge based guidance strategy is proposed by applying a direction control method based on the angle symmetry adjustment. The effective edge is constantly exchanged between two path edges as the snake robot moves. The effective edge is detected by a sensor, and is utilized to obtain the temporary target point, which is updated along the effective edge as the robot moves. The path direction is determined by the constantly updated temporary target point. So the snake robot can adjust the locomotion direction according to path edges by introducing the temporary target point into the direction control parameter. Simulations show that the snake robot can adjust the locomotion direction on the ground with unknown friction coefficients according to the path edge. It is verified that the snake robot can not only follow the desired path, but also follow the centerline of desired path.