It is the principle that chlorine can quickly form hypochlorous acid (HOCI) in water.
Bleach powder can be hydrolyzed into hypochlorous acid after being added to water.
The hypochlorous acid molecule is small in size and neutral in charge. It easily penetrates into the bacteria through the cell wall, inhibits and destroys various enzyme systems in the bacteria (mainly triose phosphate dehydratase is more sensitive to HOCl), causing the sulfhydryl group to be oxidized. Destruction affects the oxidation-reduction effect in the bacteria, causing glucose metabolism in the body to become impaired, leading to the death of bacteria and achieving the purpose of disinfection.