On the basis of the infrared radiation difference between ships and the sea surface, it is possible to use infrared detectors to identify target ships. The surface temperature field of the ships obtained by CFD software and the rough background sea surface field established by Blender software were used, and the transmittance in the oceanic atmospheric environment was calculated using the Modtran atmospheric software. Based on reverse Monte Carlo method, a thermal imaging algorithm was developed to obtain the 8 μm~12 μm infrared thermal images under different detection conditions. The results show that the infrared features of the ships in the thermal image are mainly concentrated in the chimney and power plant compartment, which is the main location for identifying the target. As the detection height increases, the difficulty of identifying the infrared features of the ships increases, and the detailed target features can be captured by adjusting the camera focal length.