Target video generation method, device and system based on monitoring and medium

The invention discloses a target video generation method, device and system based on monitoring and a medium, and the method comprises the steps: obtaining the real-time position of a target object, and determining whether the target object enters a monitoring region or not according to the real-time position; when it is determined that the target object enters the monitoring area, the position of the target object is measured again to obtain a positioning position; adjusting the angle and the focal length of the monitoring camera to enable the monitoring camera to be aligned with the target object in real time, and outputting a first response signal; carrying out starting time point marking on the monitoring video according to a time point at which the first response signal is generated; when it is determined that the target object leaves the monitoring area, a second response signal is output; according to the second response signal, a monitoring video is marked with a time point at which the second respons