By setting up a test platform for the cooling system of highpower LED headlamps, the temperature control effect evaluation tests were carried out with water and liquid metal respectively. The research results show that liquid metal has a more significant cooling effect. When the peristaltic pump speed is 100 r/min, the convective heat transfer coefficient of liquid metal is 15 times that of water, which is mainly due to the large thermal conductivity of liquid metal. In order to further optimize and improve the heat dissipation performance of liquid metal, the fluid mechanics simulation method was used to systematically study the influence of the flow rate, flow path structure and other factors on the temperature control performance of LED lamps, and a new cold plate runner structure was designed by which the temperature control effect of liquid metal was improved effectively. The research also has reference significance for other high heat flux heat dissipation systems including high power LED lamp cooling system.