A video surveillance system includes at least two camera and an analysis device. The at least two cameras include a first image camera and a second image camera. The method includes: separately obtaining, by the first image camera and the second image camera, a photographed first image and a photographed second image; obtaining indication information of a target task; separately obtaining first execution result information and second execution result information of the target task based on the indication information of the target task; sending, the first execution result information and the second execution result information to the analysis device; and determining, by the analysis device, third execution result information of the target task based on the first execution result information and the second execution result information.