Abstract: In the process of ore or rock transported in the orepass，the damage of the orepass lining caused by the collision between ore or waste rock and orepass wall is more serious.It is of great significance to determine the trajectory and position of the ore or waste rock before them collision with orepass wall to ensure the stability of the orepass wall.Taking the main orepass from -40 m to -71 m of a certain mine as an example， the similar test platform of the orepass section is established. According to the kinematics theory，combined with the similarity experiment， the three-dimensional trajectory equation of the ore or waste rock moving in the orepass before their first colliding with orepass wall.The study results show that the impact position of the ore calculated by theory is slightly lower than that of the ore in the experiment， and the error is less than 4.84%，the theoretical calculation and experimental results are in good agreement with the test results of the case mine.The study results can provide the basis for determining the impact area of the orepass wall，the design and the optimization of the orepass system，the treatment and repair of shaft and the formulation of orepass management scheme.

Key words: Underground mining, Orepass wall, Ore movement, Impact failure, Trajectory equation, Initial collision position