Meltblown cloth masks are effective in preventing novel coronaviruses. The fiber diameter of meltblown cloth can reach 0.5-10μm, which can filter out the virus attached to liquids. In clinical practice, novel coronaviruses are 80-120 nm in size and are usually ejected on tiny liquids such as saliva, which can be effectively prevented by meltblown cloth masks. Not all masks can block the novel coronavirus, and not all masks can prevent 100% of the virus. A distance of about 1 meter between people is required for better prevention of infection. The most widely used and effective clinical masks are surgical masks and N95 masks.