Abstract: A new kind composite was prepared by using polytetrafluoroethylene (PTFE) as matrix and filled with different contents surface treated MWCNTs by “cold pressing and sintering”. The flat type small punch test for material performance is introduced for measuring the mechanics properties of the prepared material. The flat head small punch test can obtain rich information of the mechanic properties by using small amount of material. A series of curves of load displacement were obtained and these curves show that the different surface treatments and different contents MWCNTs will produce different enhancement effects. By the SEM of PTFE composites analyzing, it is found that the MWCNTs lead to the fibration and toughness of PTFE.