This　paper　designs　and　implements　a　high　speed　image　transmission　board　of　external　DDR3　SDRAM　based　on　PCI-Express　to　meet　the　requirement　of　high　frame　rate　in　high　speed　image　data　transmission　system.　Transmission　board　uses　XILINX　Kintex7　series　chip　XC7K70T　as　the　master　chip,　through　the　PCI-Express　DMA　logic　for　data　exchange　with　the　host　computer,　and　uses　external　DDR3　cache　to　solve　the　problems　of　high　frame　rate　and　real-time　in　large　amount　of　data　transmission.　Transmission　board　uses　LVDS　high-speed　differential　interface　as　an　external　interface　with　the　design　of　a　set　of　LVDS　interface　timing.　In　the　experiment,　the　gray　scale　visible　image　with　1024*1025　byte　size　is　transmitted　and　tested.　It　can　verify　the　transmission　rate　of　50　frames　per　second　respectively,　and　the　data　transmission　is　stable　and　reliable,　which　can　provide　some　reference　value　for　high　speed　data　transmission　system.