The invention relates to a self-tightening sealed optical glass window of a constant volume comb, belonging to the field of the constant volume bomb designing and sealing technology. The optical glass window concretely comprises an end cover, a sleeve, optical glass, a bolt, a first sealing gasket and a second sealing gasket. The end cover comprises an observation hole, a cylindrical ring convex end surface, a screwed hole end surface, an optical glass counter bore seat end surface and an outer edge, wherein the optical glass counter bore seat end surface of the end cover is sequentially provided with the first sealing gasket, the optical glass and the second sealing gasket, and the centers of the four are coaxial; the sleeve is arranged at the other end of the second sealing gasket, and covers the optical glass and the second sealing gasket; a through hole of the sleeve is aligned with the screwed hole of the screwed hole end surface of the end cover; and the optical glass is compacted through bolt fixing so as to form an initial sealing condition. According to the invention, a self-tightening sealed manner is adopted, which has a better sealing effect under an environment with a higher pressure; the mounting time of the optical glass is reduced; the problems that the optical glass is damaged and the sealing gaskets are replaced often are solved; and meanwhile, the sealing performance of the constant volume bomb is remarkably improved.