Abstract: With the traditional slices method, it requires recalculating the geometric parameters of the soil slices when searching the sliding surface, leading to large calculation workload. It's also difficult to ensure that the sliding surface obtained from searching is the global most dangerous one. In this text, the global optimization software of 1stOpt is used as the tool. Based on the circular slip surface integration method, Fellenius and simplified Bishop analysis methods are used to search the global most dangerous sliding surface of the waterless homogeneous slopes. The results are very satisfactory.