Abstract: This paper proposes the non-timed based robot trajectory planning method in order to overcome the disadvantage of the traditional time based planning in the non-structured environment, and designs the control law according to the speciality of this method. With this planning method, robot can automatically stop itself when it meets the obstacles; and when the obstacles were cleared away, the robot can go on its motion along the original planning. It avoids the damage of the system and the re-planning of the task, enhances the capability of the system to deal with the uncertainty events.