The unmanned target vehicle is the target of all kinds of guided weapons in the experiment and test stage. In order to test the hitting accuracy of guided weapons under the conditions of different driving speeds, the unmanned target vehicle should be able to complete path selection and path planning under the conditions of different speeds. In order to solve this problem, this paper proposes a path planning algorithm for unmanned target vehicle which can be applied to different speed conditions. This algorithm is improved on the basis of the traditional A ∗ search algorithm. Combining the heading angle constraint and arc search method, and establishing the corresponding relationship between vehicle speed characteristics and search step length. This improved A ∗ algorithm is more in line with the characteristics of vehicle driving. In order to verify the effectiveness of the algorithm optimization, MATLAB was used for simulation verification. The results showed that: The improved A ∗ algorithm in this paper meets the steering limit of unmanned target vehicle, it can solve the problem of path planning at different speeds (30, 45, 60 km/ h). The experiment on remote sensing map proves that it can provide a new solution for the path planning problem of unmanned military target vehicle at different speed.