Cooling of server is getting more attention these years, which directly influence the efficiency of data processing, storage, and telecommunication. In order to solve the hot issues of sever, a thermal simulation model was built. Finding that the hotspots were mainly concentrated in CPU and Northbridge chips. With regard to CPU, the structure optimization analysis of CPU heat pipe radiator was carried out without changing the volume of heat pipe radiator. The fin thickness and fins number of heat pipe radiator were optimized. The optimized radiator could reduce the CPU hotspot temperature by 5.3%-9.09%. With regard to North Bridge chip, a chip-level cooling method based on Peltier effect was proposed. The cooling performance of thermoelectric cooler was investigated by experiments, and the best working current under different wind speed and cooling load was explored. Compared with the original heat dissipation method (non-thermoelectric cooler), the thermoelectric cooler could improve the starting characteristics and response characteristics of heat dissipation radiator, and the added thermoelectric cooler could reduce the temperature rise of North Bridge chip by 4.45%-31.12%.