The utility model provides a waterproof dimmer switch of RS65 motorcycle, the 1# static contact, the 2# static contact, the 3# static contact is moulded plastics on waterproof change light board, the movable contact spring spring, the steel ball spring is installed in the smooth piece recess of waterproof change, it goes into the movable contact spring spring to become light movable contact spring card, the steel ball card advances the steel ball spring, place the smooth piece of waterproof change on the waterproof change light board, waterproof change light support cover the smooth piece of waterproof change and with waterproof change light board in close contact with, waterproof change light support is detained fixedly with waterproof change light board mutually, waterproof change light support wraps up smooth piece of waterproof change and waterproof change light intralamellar part circuit completely, the buckle of waterproof change light button is through the smooth piece contact of waterproof change light support and waterproof change, waterproof change light button covers waterproof change light support completely, when waterproof change light button one end pushes down, become the light movable contact spring and contact with 1# static contact, 3# static contact simultaneously, when the waterproof change light button other end pushes down, become the light movable contact spring and contact with 2# static contact, 3# static contact simultaneously.