Abstract: Based on the research of Canny operator edge detection theory, aiming at the shortcomings of the Canny edge detection algorithm in Gaussian filtering, gradient calculation and determination of high and low thresholds, this paper proposed an improved wavelet transform, replaced Gaussian filtering to reduce the noise of the picture, and optimized the original gradient amplitude and direction, an improved iterative algorithm was used to calculate the high and low thresholds. MATLAB simulation experiment was used to compare the edge detection algorithm of optimized Canny and traditional Canny. The results showed that the optimized Canny edge detection algorithm can make the detection results have more edge details and improve the detection precision and accuracy.