Coating-preventing inspection window of vacuum coating chamber

The utility model discloses a coating-preventing inspection window of a vacuum coating chamber. The coating-preventing inspection window comprises an inspection window small neck communicated with the vacuum coating chamber, wherein the inspection window small neck is provided with a flange; the flange is provided with left and right flange discs, the inner side walls of the left and right flange discs can form a cavity chamber, the cavity chamber is internally provided with a baffle, and the lower part of the flange is provided with a round quartz glass inspection window; the baffle is a round thin plate, the corresponding cavity chamber is a round cavity chamber, and the baffle is provided with two symmetrical strip-type slits along a radial direction, the center position of the baffle is provided with a revolving shaft, and the revolving shaft is connected with a driving motor; the lengths of the slits and the radial dimension of the quartz glass inspection window are same, when the baffle rotates to one a