The invention discloses a network video recorder (NVR) remote screen control method, screen control device and screen control system. The method includes the following steps that: S01, receiving a remote mouse event transmitted by a remote terminal and a local mouse event; S02, creating a virtual input device simulation mouse, parsing the local mouse event or the remote mouse event into target data, and injecting the target data to a core to drive the simulation mouse; S03, reading YUV data responding to the mouse events in the core and displaying the simulation mouse; S04, encoding the displayed YUV data to form a real-time data stream; and S05, responding to a request of the remote terminal and uploading the real-time data stream to the remote terminal. According to the network video recorder (NVR) remote screen control method, screen control device and screen control system of the invention, a plurality of network video recorders can be controlled remotely through the mouse, and therefore, and configuration cost can be reduced, and centralized control on front end display output can be realized.