According to one embodiment of the present invention, a control method for a water purifier comprises the steps of: filtering inflowing water so as to generate purified water; extracting the generated purified water; measuring the flow rate of the purified water extracted per unit time; flushing a filter part by using purified water generated in the filter part, when the extraction of the purified water is complete; and draining the flushed water to the outside through a residential water outlet of the filter part, wherein, in the purified water generation step, discharging of residential water generated in the purified water generation step is blocked according to the accumulated flow rate during a one-time extraction of the purified water, calculated on the basis of the flow rate of the purified water.