A method of infrared imaging modeling of tank target was proposed. Firstly, the geometric model of the tank target was established with the method of spot disassemble and plate atom. Secondly, the thermal equation of the different parts of tank was established on the basis of heat transmission theory, and the infrared radiation intensity within a certain wavelength range was acquired. The intersect model of missile-target in time and space was built up according to their relative motion characteristic. Finally, the infrared images of tank in various target-missile intersections were acquired by computer simulation. The simulation results show that the infrared imaging model is correct and feasible.