Abstract: This invention provides a flow through type ultraviolet LED disinfecting apparatus, and a top cover and an outer cylindrical body are connected by a thread; a transparent inner cup body has a water holding tank inside for containing water, and there is a water pipe at the top of cover; a depth of the inlet water pipe reaching into the water holding tank has greater efficient than tank without pipe; a pipe mouth at one end of the inlet water pipe reaching into the water holding tank corresponds to a LED disinfecting light; the outer cylindrical body is tube-shaped, a side wall body and a bottom plate; the side wall body is sleeved outside the transparent inner cup body; a bottom of the transparent inner cup body contacts with the bottom plate of the inner cylindrical body; he circuit board with LED disinfecting LED is fixed at the bottom plate.