A cruise missile hierarchical path planning algorithm was put forward based on Voronoi diagram and improved genetic algorithm (IGA) for application of the cruise missile path planning. The algorithm establishes the threat model based on Voronoi diagram to describe the planning environment and generate the initial paths and navigation nodes. It involves variable length chromosome integer encoding, takes advantage of backtracking depth priority algorithm to generate the initial population, and appropriate genetic operators were designed. Then the simulation experiment was conducted, and the result was compared with genetic algorithm (GA), this method can improve the speed and optimality of cruise missile path planning.