With the increasing mission complexity and environmental uncertainty of UAV， the requirements for route planning also increase， and the complexity of the route planning problem gradually increases from single UAV route planning to multi-UAV planning， and from single mission to multi-mission. To find a solution to the UAV route planning problem， a comprehensive analysis from aspects of concept， connotation， task modeling and algorithm analysis is presented. To solve the problems of existing route planning algorithms， such as， poor optimal path effect， slow convergence speed and tendency of falling into local optimization， applications and problems of UAV route planning with A* algorithm， particle swarm algorithm， genetic algorithm as well as ant colony algorithm are analyzed， and directions of algorithm optimizations and improvements are proposed.