Higher concentrations of alcohol disinfection are not better. The mechanism of alcohol sterilization generally includes two aspects. First, alcohol can make the pathogen’s protein spatial structure change, leading to protein denaturation, coagulation, and thus the loss of biological functional activity, and then the pathogenic microorganisms suffered serious damage. Secondly, alcohol can also directly damage the cell wall of bacteria, leading to its pathogen lysis. Therefore, in order for alcohol to play an efficient role, it must have the right permeability, and the optimal permeability is 75%. When the alcohol concentration gradually increases when it will affect the permeability, resulting in alcohol can not penetrate into the pathogen inside, too high alcohol concentration will directly solidify a large number of pathogens into clusters, the bacteria in the clusters can not achieve a high bactericidal effect. When the alcohol evaporates, the bacteria inside will continue to reproduce and continue to spread the disease. Currently, a concentration of 75% alcohol is most commonly used, which also has an inactivating effect on novel coronaviruses.