Owing to its good tribological and mechanical properties, polyamide material was widely applied to prepare sliding mechanical parts. A lot of studies confirmed that adding different functional materials or surface modifications to polyamide could reduce the friction coefficient, improve wear resistance and reduce water absorption, so as to prolong the service life of polyamide parts. This paper summarized the common reinforcement methods of polyamide materials: blending, surface modification and filler. The reinforcing mechanism of different fillers and polymers, the effects of different methods on the tribological properties, mechanical properties and water absorption of polyamide composites, and the preparation methods of polyamide composites have been systematically discussed.