Abstract: Aiming at the problem that the center point of the traditional Census transform window in stereo matching is easily affected by the external environment and the matching accuracy of some depth discontinuous regions is low, astereo matching algorithm based on improved Census transform and propagation filtering is proposed. In the initial matching cost calculation, the improved Census transform is fused with the color and gradient cost. At the same time, the propagation filter is introduced in the cost aggregation stage to maintain the edge of the parallax space image, which is not affected by the window size of the traditional local algorithm.Then, in the parallax processing part, the winner-takes-all(WTA) algorithm is used to calculate the initial parallax.In the following disparity optimization part, the method of left and right consistency detection and median filtering is used to obtain the final disparity map. Experimental results on Middleburry show that, compared with the traditional Census algorithm, the matching accuracy of the proposed algorithm is significantly improved, and the algorithm has good real-time performance and robustness.