According to the product design principle, the double film structure of SiO2/ITO films was designed and prepared. The preparation process is as follows:Si target (purity 99.85%) was used, and ITO target (purity 99.85%) was mixed with 90% indium oxide (In2O3) and 10% tin dioxide (SnO2). TN (Twist Nematic liquid crystal) sodium-calcium glass substrate was selected, size 16"×14"×1.1 mm, one side coating. Through magnetron sputtering and continuous coating magnetron sputtering, production line test equipment was used to carry out process design for TN series glass, requiring block resistance uniformity range of 70-90 Ω/sq., coating in a 10 000 clean workshop at control humidity of 30%-70%RH. The TN sodium-calcium glass substrate was placed on the frame, the height of the frame was approximately equal to the height of the coating equipment, and the frame was transported by the conveyor belt through the coating machine for coating. The first vacuum extraction treatment of the coating machine was carried out to ensure the stability of the atmosphere during the coating process, and then it was sent to the inlet chamber, transition chamber, variable speed chamber, and then the coating chamber for Si target and ITO target for coating. The deposited Si film was oxidized to form a SiO2 film, and after coating, it was sent to the variable speed chamber, transition chamber, and outlet chamber in turn to fill air for natural cooling to prevent the glass from being damaged due to the large pressure difference between inside and outside.