In order to eliminate UAV potential safety hazard in expressway patrol, and avoid the crash risk because of collision, the paper uses 3D dynamic collision prediction and optimal problem dynamic collision avoidance arithmetic to propose an UAV dynamic collision avoidance technology that is appropriate for three-dimensional space. And then, it uses 5G communication technology to construct communication network, when UAV meet random obstacle, it can make it maintain smallest safety clearance. Simulation results show that, paper’s technology is better than the technology based on optimal geometric in algorithm efficiency, route cost and route quality 3 aspects, the collision avoidance strategy is useful.