In order to explore the lubricating effect of liquid crystal as lubricant on the silicon carbide/polyimide(SiC/PI) rubbing pair system and the factors affecting the friction reduction performance of the system,monomolecular liquid crystal 4-cyano-4′-n-pentylbiphenyl（5CB）and mixed liquid crystal of 90% 5CB and 10% 4′-cyano-［1,1′-biphenyl］-4-yl 4-ethylcyclohexane-1-carboxylate(2CEPPN) were selected as lubricants respectively,and the tribological performances of the system were investigated by UMT-3 micro-friction tester.The results show that both the monomolecular liquid crystal and mixed liquid crystal have better friction reduction effects as lubricant on SiC/PI rubbing pair,and can even reach the superlubricity state.The mixed liquid crystal has better friction reduction effect than the monomolecular liquid crystal,it can achieve good friction reduction effects at low loads and high speeds,and can enable SiC/PI rubbing pair to achieve superlubricity for a long time.