The invention discloses a crowd behavior model analysis and abnormal behavior detection method under a geographical environment. The method comprises the following steps that: video monitoring signals can be captured, and crowd movement regions in a monitoring scene are set, and video monitoring crowd images are obtained, and geographic spatial mapping processing is performed on the crowd movement regions; measurable crowd movement fields are calculated through using an optical flow method under geographic reference, and the crowd movement fields are converted and mapped to polar coordinate reference; according to the distribution situation of the crowd movement fields under the polar coordinate reference, statistical analysis is performed on the crowd movement fields at each main direction of the polar coordinate reference, and then, crowd movement models and crowd movement trends under the geographical environment can be judged, and crowd movement rate at each main direction can be estimated; and based on the analysis results of the crowd movement models, movement trends and movement rate, detection on crowd abnormal behaviors such as movement rate mutation, movement trend mutation, reverse walking, sudden aggregation and sudden scatter is performed. The crowd behavior model analysis and abnormal behavior detection method of the invention can be widely used in areas where crowds are prone to aggregation.