Near infrared single photon detector is an important part of quantum secure communication, and reducing its operating temperature is the key to improve the detection efficiency. In this paper, the characteristics of temperature difference of aluminum alloy radiator and vapor chamber were discussed, the relationship between the starting speed and the change of heat flux was studied, the influence of heat flow density on the thermal resistance value of the cooling device was analyzed, and a system for experimental verification was build. The results show that the cooling performance of the vapor chamber is better than that of the aluminum alloy radiator, the temperature difference can be controlled within 2℃, and the starting speed of the vapor chamber is faster. In addition, the size of the radiator has a great influence on the heat dissipation performance. When the same heat flux is loaded, the large-size vapor chamber can dissipate more heat. Therefore, the use of a larger vapor chamber will be conducive to improve the detection efficiency.