In order to solve the problem that the UAV group can achieve autonomous route planning in designated airspace from the starting point to the target, moreover the system complete the task with the high level of synergy and efficiency, a new method of autonomous route planning of UAV group was presented. Analyze moving track points of the group and its characteristics, and estimate all the tracks by using established mathematical estimation model. The result of simulation and estimate reveal the method is correct and effective, moreover it optimize the conventional method of route planning with inherent defects, which is beneficial to the realization of UAV group in reality.