Aiming at the air tightness ofSiCp/Al composites with high volume fraction, the influence of plating and orientation of raw materials on surface helium adsorption properties was systematically studied. It was found that after plating treatment on the high volume fraction of SiC_p/Al composite, the qualified rate of the helium adsorption capability increased 20%, and the qualified rate increased gradually with the increase of coating thickness. Difference in mechanical processing has little influence on the qualified rate of the helium adsorption capability. The raw material is anisotropic, the qualified rate of transverse cutting is 91%, and the longitudinal cutting is 68%.