Based on the intrinsic motivation mechanism, this paper builds up a new kind of path planning method. The curiosity function existing in such a mechanism is extended from state-based to motion-based, and the corresponding motion choosing mechanism is designed, which is more biologically explicable. The energy function of the mobile robot under the environment with obstacles is designed, which is used to decide the learning direction. Simulation results show that the proposed path planning method can help the robot learn its environment, and achieve obstacle-free navigation from any start position. What is more, the energy function is environment independent, and even though the target position changes, the robot can still complete the tasks through relearning, which proves that the proposed method is with high autonomy and not task specific.