A gun mounted light, having a light, a rail disposed at one side of the light, and a clamping assembly movably connected to the rail. The clamping assembly has a mounting seat movably connected to the rail, and a movable clamp connected at one side of the mounting seat. A fixed clamp cooperating with the movable clamp is provided on the mounting seat. A side of the mounting seat distal from the movable clamp is connected with a handle. The movable clamp is connected with one end of a pull rod; the pull rod is rotatably connected with a cam on the handle. A first resilient piece is provided between the cam and the mounting seat. A side of the mounting seat proximal to the light is provided with a sliding groove cooperative with the rail. A locking component is provided between the first resilient piece and the mounting seat.