Abstract: The structure and principle of reflective fabric were described firstly. The aluminum vacuum technology for forming the reflective layer was reviewed. The theory of aluminum vacuum machine was introduced,including vacuum system and vacuum chamber mainly. Slide valve pumps,Roots pumps,oil booster pump,oil diffusion pump were run sequentially when vacuum system working and the winding up chamber and the film coating chamber inside the vacuum chamber were in parallel,wherein the winding up chamber and the film coating one showed the volume ratio of 3∶ 1,the pressure of the former was more than 10 times compared with the latter’s when running. Secondly,by analyzing the binding force of the aluminum layer,temperature and humidity,the effect of which on aluminum vacuum was elaborated. The thickness of the aluminum layer was 150~400 Å on general in order to ensure the binding force of reflective materials,the gap of evaporation boats was 100~150 mm,and the distance of which to the cooling roll was 160~240 mm. We chose oil glued films when the air humidity was greater than 85%,or the vacuum would be below standard.