The present invention provides a method of forming a passivation layer of a MOS device, and a MOS device. The method of forming a passivation layer of a MOS device includes: forming a substrate; forming a dielectric on the substrate; patterning the dielectric to expose a part of the substrate; forming a metal on the exposed part of the substrate, and the dielectric; forming a TEOS on the metal; forming a PSG on the TEOS; and forming a nitrogen silicon compound on the PSG. Therefore, the cracks problem of the passivation can be alleviated.