The invention provides a mapping method and system of a cloud terminal external device, a server and a cloud terminal. The method comprises the following steps: receiving a device list of external devices connected with the cloud terminal sent by the cloud terminal; determining device types of the external devices according to the device list; determining a target device that needs to use video streams to perform data transmission according to the device types of the external devices, and the device type of the target device; generating a mapping request according to the device type of the target device; creating a virtual device having the same device type as the target device according to the mapping request; and establishing a data logic link between the virtual device and the target device, so that the virtual device and the target device perform data transmission. The external video function of the cloud terminal is effectively achieved, the transmission rate and the instantaneityof the video stream data are improved, and the efficiency and the accuracy of determining the device types of the external devices and establishing the corresponding virtual device.