The invention relates to a crowd gathering detection method for a monitor video, comprising the following steps: firstly measuring to realize reliable extraction of a foreground region via pixel gray statistics and edge consistency, then using an improved Haar human detection method based on area normalization to extract the foreground region comprising a human body, finally realizing crowd gathering detection through counting distribution character of a Fast feature point of the foreground region comprising the human body. A foreground extracting method based on the pixel gray statistics and the edge consistency is short in initial training time and low in false alarm rate. Because external expansion range after normalizing areas to be detected with different sizes is the same, the human body detection method of the area normalization gives consideration to detection accuracy and efficiency. Region feature extraction based on the Fast feature point and the crowd gathering detection are strong in operability in a real system by using a region area as a weighting basis. Using feature point weighted value to represent the human body could effectively overcome a shelter. The crowd gathering detection method of the invention is well-adapted.