Abstract: Using the vertical continuous straight line coating production line and vacuum magnetion sputtering technique, Nb₂O₅/SiO₂/Nb₂O₅/SiO₂/CN_x multilayer nano hard anti-reflection film was fabricated on the surface of the glass, and its transmittance, hardness and physical and chemical properties were studied. The results show that by introducing linear anode layer ion source, and and the forming of a new magnetron sputtering coating process, the surface hardness of diamond face glass has reached 994. 8 HV, more than 2 times of that of the ordinary glass; more than 94% of the visible light, can penetrate it, demonstrating good anti-reflection; the attenuation of transmittance is △T < 0. 1% after it was acid/alkali/solvent/heat treated, showing excellent physical and chemical properties.