Bore-sight error estimation for the mobile mapping system (MMS) plays an extremely important role in the quality of the point cloud, especially when the MMS scans the same area from different routes and angles, unideal bore-sight error estimation seriously reduce the point cloud registration accuracy. For fine calibration of the bore-sight error, a bore-sight error self-calibration method based on plane fetures of MMS is propsed, the computing model of point cloud of MMS is given, the Gauss-Helmert adjustment model is established based on plane features of MMS, and the solution is derived based on the least square method. The experiment results show that the bore-sight error is easily computed by the proposed method, and the computation result is reliable and effective