It is necessary to calibrate the relative pose between the three-dimensional (3D) lidar and the GPS / INS integrated navigation system for their combination. Because of the phenomenon of point cloud distortion in vehicle moving process, a method of coordinate correction for laser scanning point in single frame point cloud is proposed. Aiming at the calibration problem, a method of extrinsic parameter calibration is proposed, based on ICP algorithm, hand-eye calibration model, and least squares method. Monte Carlo simulation results show that the algorithm is accurate and effective. The calibration experiment is carried out on the unmanned vehicle labor-atory JJUV-6, and the 3D relative pose relations are obtained. It shows that after calibration the effect of 3D point clouds reconstruction is better, and the overlapping degree of point clouds is close to the registration effect. For the purpose of applications, it can meet the needs of 2D map construction and 3D environment reconstruction.