In order to solve the problems of collapse and sliding blocks of rock slopes engineering, it is crucial to analyze the stability of blocks. In this paper, we take the rocky and high steep slope of Shenxianju Scenic Area in Xianju County, Zhejiang Province, as a research instance to investigate the improvement of block stability analysis efficiency and visualization. Based on the coordinate projection method, the determination method of block geometric conditions and the calculation method of stability coefficient is proposed. Then, through combining the coordinate projection method and UAV measurement technology, the CPS program suitable for analyzing the stability of planar polyhedron blocks and curved surface blocks in rock slope engineering has been developed based on MATLAB to realize the spatial representation and visualization of unstable blocks. The program can determine the geometric conditions of blocks conveniently, realize the stability analysis and visualization of blocks. Also, an engineering application shows that the study can effectively and accurately deal with the common engineering geological disasters such as rockfall and collapse. The developed program can realize the visualization of rock slope model, its analysis results are basically consistent with the Q-slope method. That is to say, this analysis method for block stability is reliable, which can greatly improve the efficiency of block stability analysis of rock slope with practical engineering significance.