Cotton gauze masks cannot protect against viruses. According to the notice on the guidelines for the use of masks for the prevention of novel coronavirus pneumonia issued by the National Institute for Disease Control and Prevention, it can be seen that cotton gauze masks, sponge masks and activated charcoal masks have no protective effect against viral infections. The main antiviral material for masks that can provide protection against the disease is meltblown cloth that has been treated with an electropolar process. The gap between the fibers of meltblown cloth is significantly smaller than that of cotton yarn, so it is more effective in blocking slightly larger diameter particles. At the same time, meltblown cloth can also rely on the electrostatic adsorption of very small particles within the fiber filaments after the electret process, so as to complete the role of anti-virus. On the contrary, cotton gauze masks with large fiber spacing and no electrostatic adsorption function can only be used for daily dust control and have no effect on anti-virus.