The method for quickly detecting vehicles in aerial traffic video, the steps are as follows: step 100, adopt global motion estimation in the space-based encoding part, determine the global motion vector of the background; step 200, calculate the residual value according to the global motion vector, and segment the background area and the motion area ; Step 300, judge whether they are all background areas, transfer to the next frame for the images that are all background areas, and perform step 100; otherwise, for the motion area of the image, perform step 400; step 400, first determine an offset on the ground part Low but still able to correctly segment the adaptive gradient threshold of each object, and perform preliminary marker extraction; then introduce the two parameters of area and catchment depth, and further screen the extracted markers to determine the final marker points; then use the marker points as The minimum value of the area is divided by VS watershed; finally, the area is merged according to the texture information of the area; step 500, the shadow is detected in the HSV color space, the false target is filtered out, and the vehicle is finally detected. The invention solves the problem that the calculation amount is large when decompressing the aerial image and detecting the moving target, and it is difficult to meet the requirements of real-time and robustness at the same time.