The threats of infrared reconnaissance, surveillance, and guidance weapons to directly buried heat pipelines are increasing with the development of modern infrared technology. Therefore, it is necessary to conduct extensive research on thermal infrared camouflage technology for directly buried heat pipelines. Based on the principle of heat transfer, this paper establishes a numerical model of the temperature of the directly buried heat pipe and analyzes the influence of the buried depth of the pipe, the mixing of cold and hot fluids, and the coating of thermal insulation materials on the thermal infrared camouflage effect. The analysis results provide an important reference for the thermal infrared camouflage design of the directly buried heat pipe.