The invention relates to the technical field of indoor environment sterilization and disinfection, in particular to a sterilization and disinfection device and a sterilization and disinfection method.The device comprises a cabinet body, ultraviolet lamps are externally arranged on the cabinet body and can generate at least 10 mg of ozone per minute, an air inlet is formed in the cabinet body, a first catalytic net is arranged on the inner side of the air inlet, a fan is arranged, and an air outlet is arranged on the cabinet body and communicated to the inner side of the first catalytic net, acontrol panel is arranged, an automatic control induction system is used for controlling the operation of the ultraviolet lamp and the fan; the fan, the control panel and the automatic control induction system are all arranged on the cabinet body; the automatic control induction system is electrically connected with the control panel, and the total power of the ultraviolet lamps is at least 300 W. The sterilization and disinfection device solves the problems that in the prior art, the efficient, comprehensive and thorough sterilization and disinfection effects are difficult to achieve, and harmful substances are left after sterilization and disinfection, can achieve efficient, comprehensive and thorough sterilization and disinfection, and is environmentally friendly, free of pollution andfree of residues of the harmful substances.