In order to solve the problem of large errors in the ranging results caused by the interference of noise when the lidar locates the echo peak. Based on the twotime Kalman filter algorithm, this paper proposes an algorithm that can effectively suppress noise. First, perform Kalman filtering on the timedomain echo, then perform the perioddomain Kalman filtering again on the peaktopeak position difference in consecutive periods, and finally map the peaktopeak position difference to the true spatial distance. Experimental results show that the distance variance after processing by the above algorithm is reduced to less than 6% of the denoising front error, and the average absolute error and root mean square error are reduced to about 20% to 50% before denoising, indicating the filtering algorithm designed in this paper. It can effectively reduce the influence of noise and make the ranging result more stable.