Black silicon with textured surface was prepared on mcSi by metal assisted chemical etching (MACE) technique using Ag element. The surface Ag residues, morphology and optical absorption of the prepared black silicon samples were characterized and analyzed by energy dispersive spectrometer, scanning electron microscope and reflectivity tester. On this basis, solar cells were fabricated with the black silicon samples with standard processes of diffusion, etching, PECVD coating, screen printing and sintering. And their electrical and electroluminecence (EL) properties were characterized and analyzed by IV and EL test. The results show that compared with the regular and uniform circular texture surface without Ag residues, the surface morphology of black silicon samples with Ag residues was disorderly in direction and different in depth. The efficiency of the related solar cell was 3.03% lower than that of the normal cell due to the sharp boundary around the pit and the irregular shape.