An identification device for a tin surface of float glass includes an outer shell (3), a gas discharge light tube (5) and a power source. The gas discharge light tube (5) and the power source are arranged inside the outer shell (3). An irradiation window is installed on the outer shell (3) corresponding to the position of the gas discharge light tube (5). A UV light-absorbing mark (6) is provided on the inner or outer surface of the irradiation window, and the tin surface of float glass can be visually identified according to whether the mark (6) can be observed.