To achieve the capture,track and lock of suspicious targets in the long distance,a SDI IR image transmission method is proposed.Four LVDS digital signals were decoded firstly,and then image format was recoded according to the SMPTE296M standard because Virtex-5 of FPGA has the abundant logic resources.Finally,the real-time data transmission of lossless and high-definition image was realized.The experimental results show that this method can improve the efficiency and stability of the image transmission comparing with other digital image transmissions.This method has a good effect in the practical application.This research results provide the solution and reference for further study of artillery photoelectric tracking system.