A filtering device having UV light, that includes shell body having a water passage chamber, UV light is disposed in the water passage chamber. A glass tube set is disposed in the water passage chamber around outer periphery of the UV light. The glass tube set includes a first glass tube and a second gas tube both disposed around the outer periphery of the UV light. The lower end of the first glass tube is connected to and acts in cooperation with the lower end of the water passage chamber. The upper end of the first glass tube is separated from the upper end wall of the water passage chamber. The second glass tube is located around the outer periphery of the first glass tube. The lower end of the second glass tube is separated from the lower end wall of the water passage chamber.