Platform has a good function to baffle potential unstable rock masses movement after their falling.. In this paper, using the kinematics and mechanics theoretical theories, the velocity calculation formula of collision process between rolling rock and platform were put forward, and the horizontal movement calculation method of rolling rock moving on platform was studied. Furthermore, the rolling friction coefficient was researched on the basis of the test and the shape analysis of rolling rock. The test result showed that, the rolling rock moving velocity after collided with platform was ascertained by the normal restitution coefficient, tangential restitution coefficient and the rolling rock moving velocity before collided. The horizontal displacements of the rolling rock on platform have three parts: the horizontal span displacement above the platform before collision, the horizontal displacement between two collisions with the platform, and the rolling displacement after final collision. The displacement value can be ensured with kinematics analysis. The normal restitution coefficient, tangential restitution coefficient and the rolling friction coefficient are the important parameters to calculate the horizontal displacement of the rolling rock movement on platform. The rolling friction coefficient value between rolling rock and platform with rock blocks and detritus surface is between 0.19 and 1.05, and the value is reduced in turn according to rolling rock shape of rectangle, square, spherical and slices shape. The relationship of the rolling friction coefficient between the rolling rock shape and the platform with rock blocks and detritus surface is a good linear relation. The rolling friction coefficient of others shape rolling rock can be confirmed by interpolation method or regression formula. Then the new feasible methods to prevent potential unstable rock masses are put forward. The results help us make out a draft of geohazards prevention.