A light beam disinfection device and a method thereof are provided. The light beam disinfection device comprises a housing, a driven system, a power generating device and a light source. The housing covers a handrail. The driven system is disposed in the housing and comes into contact with the handrail. The power generating device connects with the driven system and generates electric power while the driven system is rolling. The light source is disposed in the housing and provides a light beam when receiving the electric power from the electrical power generating device. When the escalator is operating, the action of sliding the handrail is adapted to drive the driven system. The power generating device provides the electric power by rolling the driven system, and thus, the light source provides the light beam for the handrail of the escalator.
