The invention discloses a pan / tilt / zoom (PTZ) camera control method, a device and a system thereof, which can be applied to an audio / video monitoring system comprising a server, a terminal device and the PTZ camera. The method comprises the steps of: using the terminal device to receive the control command of the PTZ camera sent by the server, wherein the control command contains the coordinate parameter of the target imaging area of the PTZ camera in the current image window; using the terminal device to confirm the rotating direction, the rotating speed, the rotating time and the zoom time of the PTZ camera according to the coordinate parameter of the target imaging area as well as the equipment parameters of the PTZ camera; and using the terminal device to control the PTZ camera to rotate according to the confirmed rotating direction, rotating speed and rotating time, and control the PTZ camera to zoom according to the zoom time. The invention can be used for improving the compatibility of the audio / video monitoring system.