The detection of the weak lifting movement signal of underwater vehicle is the key point to solve the problems that underwater submarine or underwater vehicle(UV) hovers at a specific depth underwater.Based on the specific requirement,a novel detection method to realize the detection of the weak lifting movement information of underwater vehicle is proposed in this paper.The Kalman filtering technique was used to fuse the information of inertial measurement unit (IMU) with auxiliary information provided by platform compass,depthometer,and other external instruments,finally the weak lifting movement signal of underwater vehicle was detected.In addition, we set up a hardware platform that integrated a MEMS IMU with a navigation computer based on DSP and FPGA. The experimental result showed that the proposed detection method is effective.