This paper sheds new light on the effects of single-layer Boron Nitride (SBN) for vehicle interiors and exteriors on the mechanical and friction properties of polycarbonate (PC). First, the SBN is prepared by modifying the Hexagonal Boron Nitride (HBN) with the silane coupling agent KH550. PC, PC-g-MAH and SBN are evenly mixed by a high speed mixer. Next, an injection molding machine is used to prepare the PC/SBN composite material for vehicle interiors and exteriors by the melt blending mode. The findings suggest that SBN has a toughening and strengthening effect on PC when it is less than 1.6wt%, and the surface hardness and wear resistance of PC/SBN are also improved; when the boron nitride filling volume is higher than 1.6wt%, the mechanical strength and friction properties of PC/SB weaken instead. When the filling volume of SBN is 1.6wt%, the tensile and impact strengths of PC/SBN reach the peaks, i.e. 35.28MPa and 34.76kJ/m2, respectively, and 10.8%, 18.88% as high as that of pure PC; at this time, the friction factor and wear rate of PC/SBN are 14.3% and 32.3%, respectively, lower than that of pure PC.