Abstract: The existing research methods of rockfall motion have shortcomings such as complex equipment layout and single data acquisition.In the calculation process, the random distribution of rockfall trajectory is generally adopted for fuzzy processing, which is poor in accuracy.To quickly obtain the rockfall motion parameters, a inertial navigation technique is proposed.The basic principle of inertial navigation technique is introduced.Through laboratory experiment, we resolve the velocity and posture of rock sample.Compared with the high-speed camera, the accuracy of inertial navigation technique is verified.The results show that:(1) By using the inertial navigation technology, the dynamic changes of the characteristic parameters such as acceleration, velocity and angular velocity can be obtained quickly during the rockfall motion, the posture and energy change can further be calculated.(2) The collision posture has a significant influence on the rockfall collision process, which will determine the subsequent direction, velocity and impact energy of the rockfall.