According to the requirement of high real time in an infrared detection system, by studying the characteristics of the 1553B protocol, a 1553B bus interface program is proposed and the hardware and software implementation of the program in an infrared detection system is detailed. The infrared detection system of a missile is used to track space dim target, and realtime communication is required to achieve the purpose of adjusting operating parameters timely. Using BU65170 as 1553B protocol processing unit, and FPGA as the core control unit to control BU65170 to read and write messages timely and parse the received information. Experimental results show that the 1553B bus interface program has high real time and stability, and provide a feasible solution to meet the high real time in an infrared detection system.