The present application discloses a light and disinfection system and a method for disinfecting an illuminated surface by the light and disinfection system, wherein the light and disinfection system comprises an illumination module, including an illumination source； a distance sensor for detecting a distance between the light and disinfection system and the illuminated surface； and a disinfection module, including a disinfection light source and a control unit, the control unit receiving the distance detected by the distance sensor and controlling an irradiation power of the disinfection light source based on the distance, such that an irradiation amount of the illuminated surface accumulated within one disinfection circle is kept at a predetermined value.
