Some edges cannot be detected when the single property gradient edge detection is used,it affects the integrity of the detection results. To solve the problem, a new edge detection algorithm based on multigradient fusion is proposed. The algorithm first converts the RGB image into the YCbCr color space, and then extracts the luminance component Y and the color component Cb, Cr respectively. For the extracted luminance component Y, the color components Cb and Cr, combined with the depth image D, using the multidirectional circular edge detection operator calculates the gradient respectively.The four gradient images are fused to obtain the edge detection results. The experimental results show that the algorithm gains clearer and more complete results, and improves the effect of edge detection effectively.