Polytetrafluoroethylene (PTFE) composites filled bronze power in mass fraction of 40% were prepared by the method of cold press sintering,with respectively PTFE and modified PTFE (mPTFE) as matrix,bronze power as filler.The PTFE composites were sintered by three kinds of cooling processes as slow cooling,middle speed cooling and quick cooling.The effect of cooling process on the degree of crystallinity,mechanical properties,tribological behavior and sealing performance of PTFE composites were investigated.The results show that the rate of cooling has great effects on the degree of crystallinity,mechanical properties,tribological behavior of PTFE composites.The quick cooling process can reduce the degree of crystallinity and hardness of PTFE composites,and improve the tensile strength.The effect of the cooling rate on the performance of mPTFE is greater than general PTFE.PTFE composites with lower hardness can be prepared by using the sintering process of quick cooling and mPTFE,so the leakage rate of PTFE composites is greatly reduced,and sealing effect is improved.