The invention discloses a household water purifier with a function of automatically stopping water. The household water purifier comprises a base, wherein a water cavity is formed inside the base, a water inlet is formed in one side of the base, and a water guide mouth is formed in the upper part of the base; a stopper plug is connected with the interior of the water guide mouth, a push rod is arranged at the upper end of the stopper plug, and an ejecting rod is arranged at the lower end of the stopper plug; a sliding block is connected with the lower end of the ejecting rod, and the sliding block is connected with a casing pipe. When the household water purifier with the function of automatically stopping water is in use, part of water in a water tank enters a heating box for heating, sothat application requirements of a user are met; when a filter element is cleaned, a fixed cover is removed, the filter element is pulled out, and during the process the stopper plug is pushed upwardsby a spring in the casing pipe through the sliding block and the ejecting rod, so that the stopper plug is adhered to the inner wall of the water guide mouth tightly so as to stop the water, cleaningof the filter element is facilitated, and the inconvenience caused by leakage of raw water is prevented; and since the raw water can be prevented from entering the casing pipe through a protective sleeve between the casing pipe and the stopper plug, normal work of a structure inside the casing pipe can be ensured.