Nanometer water filter with automatic cleaning function

The utility model relates to a nanometer water filter with an automatic cleaning function. The nanometer water filter comprises a tank body and is characterized in that the upper part of the tank body is provided with a tap water inlet; the lower part of the tank body is provided with a tap water outlet and a purified water outlet; a filtering bucket is arranged in the tank body; a nanofilm which is positioned below the tap water inlet and has an inclined surface is arranged at a water inlet of the filtering bucket; a water outlet of the filtering bucket is connected with the purified water outlet; the lower part of the tank body is provided with a first input channel, a second input channel and a two-position three-way steering valve of an output channel; the first input channel is connected with the tap water outlet; and the second input channel is connected with the purified water outlet. The nanometer water filter provides convenience for a user to select common tap water and purified tap water freely, en