To improve the real-time performance and accuracy of the seeker decoder andreduce the effects of missing pulses and interference pulses on laser decoding, an identification method based on the digital matched filter and an adaptive extended real-time gate technique was proposed to search and track the target. The decoder system was designed and implemented based on a field-programmable gate array (FPGA) chip. The simulation and experimental results show that the code pattern identification can be completed within the current period of a set of encoded signals, and the real-time of the decoder system is good. For the 100kHz high pulse repetition frequency interference, the proposed real-time gate technique with a normal gate width of 5μs reduces its interference probability to 50% and effectively improves the anti-jamming performance of the guidance. This study is conducive to improving the accuracy and reliability of semi-active laser-guided weapons.