The present invention relates to a toilet bowl water sterilization device and a method therefor, which may electrolyze toilet bowl water stored in a toilet bowl water tank or a pipe, convert the toilet bowl water into electrolyzed water suitable for sterilization and cleaning through the electrolyzing, and sterilize various bacteria which live in a toilet bowl as well as the toilet bowl water tank or the pipe without using a toilet bowl cleaning agent, such as a chemical substance or a surfactant.
