Abstract: Aiming at the effective simulation of the DIRCM in the hardware-in-the-loop simulation, the calculated radiation energy for the laser source is 8 times of the absolute value of the aircraft radiation intensity in the band range of 3 m~5 m based on the analysis of the laser source in DIRCM and real battlefield scenario. Combined with the change of atmospheric transmission transmittance in 4 m, the change rule of radiance on the IR seeker is obtained with the change of distance between the aircraft and the missile. The simulation scheme of DIRCM in the hardware-in-the-loop simulation is designed based on the principle of realistic simulation, the energy change of the laser source is calculated with the change of distance between the aircraft and the missile, the energy of IR interference radiation energy in 1 km is set as the energy of the simulation laser source, and the energies in other distances are controlled through the attenuation slice. At last, for the purpose of improving the versatility and intelligence in DIRCM simulation, the closed loop control of simulation laser is designed, and the method of closed loop control for interference wavelength and modulation mode is studied.