Method, system and device for transmitting pictures

The invention relates to a method, a system and a device for transmitting video data. The method for transmitting the video data is applied among a video data providing device, a first video device and a second video device. In the method, the video data providing device obtains an picture coding format supported by the first video device; the video data providing device provides a picture, converts the picture into video data according to the picture coding format and transmits the video data to the second video device; and the second video device transmits the video data to the first video device, and the first video device decodes the video data according to the picture coding format to obtain the picture back. The invention really improves the phenomenon of overweight load because compression and transmission mechanisms are both arranged in a conference management device in the known technology, thereby further improving the effect of data transmission in a video conference.