The invention provides a moving target detection method aiming at a complex background, relating to detection aiming at a moving target inside the complex background and solving the problems of poor adaptability and robustness of the traditional detection method under complex conditions. The moving target detection method comprises the following steps of: acquiring an M-frame scene image of a video of a scene to be detected, and carrying out interframe differencing; building a mixture Gaussian model for a difference sequence of each pixel point; setting the false alarm rate of the mixture Gaussian model; calculating a detection threshold of each pixel point; and carrying out binarization processing on each pixel point of each frame of scene images according to the detection threshold to obtain an outline of the moving target. The invention is suitable for detecting the moving target under the complex background.