In the large-scale automatic production process, in order to test different types of TV motherboards, it is very necessary that video test sources can output different formats, multi-interfaces and multi-resolution in parallel. Through the exploration of multimedia video transmission principle and video signal interface formats, the video test signal source is designed and realized in an advanced Artix-7 series large-scale programmable XC7A100T chip, which can output both ultra-high-definition and high-definition video HDMI interface signal, and analog standard definition video signal in VGA, CVBS and YPRPB format. First of all, parallel digital baseband video signals with different resolutions and field frequencies are generated according to the principle of video display. Then, the parallel ultra-high-definition and high-definition digital video signals are converted into serial TMDS signals in order to be sent to the HDMI interface for display; and the parallel standard resolution signal is sent to the modulation module and digital-to-analog converter to become analog video signal in VGA, CVBS and YPRPB format. In particular, the parallel ultra-high-definition and high-definition digital video signals are converted into serial TMDS differential signal inside the XC7A100T chip, which saves the video parallel-serial processing chips and reduces the cost of equipment. The whole system improves the integration level of video test signal, reduces the volume of test equipment, and the manufacturers of video equipment can be more convenient to test.