To solve the problem that the vertical resolution is low when using 16-line LiDAR to realize negative obstacle detection,which leads to the difficulty of negative obstacle detection and recognition, a detection method of negative obstacle based on IMU-LiDAR is proposed.The method establishes a multi-frame LiDAR point cloud data fusion model,which can effectively use previous point cloud data and detection results to obtain more environmental information,and improve the detection accuracy of negative obstacles.The 16-line LiDAR and the self-developed IMU sensor are used to conduct the tests.The results demonstrate that the proposed method can achieve the multi-frame fusion of the LiDAR point cloud,and the detection ability of the LiDAR on negative obstacles can be further improved.A more advanced environment awareness is achieved with lower hardware costs,which shows that the method has practical application value for the study of driverless technology.