To be aimed at the transmission of welding seam video information for binocular vision welding robot, this paper uses these hardware devices, such as DaHeng image acquisition card DH-VT140, two CCD cameras and PC,in order to acquire welding seam image. And with DirectShow technology, in Visual C++6.0 environment, the paper realizes transmission and displaying of welding seam video through capturing video from the image acquisition card and function of MPEG-4 coding and decoding in DivX. Experiment results show that this method can obtain a very good welding seam video, which will provide a reference for the welding seam video information in LAN transmission and monitor in the future.