The invention provides a method for data transmission in a cloud terminal system. The method comprises the steps that audio and video transmission parameter values of a corresponding cloud terminal virtual desktop are obtained by a local terminal, wherein the audio and video transmission parameter values are used for representing the audio and video transmission capacity; if the audio and video transmission parameter values are compared with audio and video transmission parameter values of the local terminal and the audio and video transmission capacity of the cloud terminal virtual desktop is stronger than that of the local terminal, audio and video data obtained by the local terminal are offered to the cloud terminal virtual desktop, and the audio and video data are transmitted to an opposite terminal communicated with the local terminal after being coded and decoded by the cloud terminal virtual desktop; otherwise, the obtained audio and video data are transmitted to the opposite terminal communicated with the local terminal after being coded and decoded by the local terminal. According to the method for data transmission in the cloud terminal system, the transmission time is shortened and the transmission efficiency is improved.