A new method of surface smoothing based on the distance image median filtering and bilateral filtering is proposed, which can be applied to laser scanning imaging system. The method makes full use of the spatial topological information contained in the output of laser scanning imaging system, and considers the advantages and disadvantages of the bilateral filtering in surface smoothing carefully, then carries out the two dimensional processing to make surface smoothed, with maintaining surface’s shape to the maximum extent. Experimental results show that the proposed method can effectively achieve the surface smoothing, and its effect is better than traditional algorithms. Furthermore it is 8 times faster than traditional algorithms, so it can meet the real-time requirements more.