The application discloses an intelligent closestool and a descaling method thereof, and comprises the following steps: S1, starting descaling; S2, switching a
reversing valve downstream of an instant heater to a state of opening a cleaning port communicated with a water spraying body; S3, starting a liquid pump connected with a switching valve upstream of the instant heater, and the liquid pump stays for T1 time in the state of opening the cleaning port of the
reversing valve, so as to pump descaling liquid in a
liquid storage tank communicated with the liquid pump to the water spraying body and
discharge the descaling liquid from a water outlet of the water spraying body; S4, switching the
reversing valve to a state of opening a descaling port communicated with the
liquid storage tank, and the liquid pump is in an open state for T2 time, so that the descaling liquid circulates in a loop formed by the
liquid storage tank, the liquid pump, the switching valve, the instant heater and the reversing valve for T2 time. By arranging steps S2 and S3, the descaling liquid in the
liquid storage tank can be used to replace residual cleaning water in a passage between the switching valve and the water spraying body, so that
dilution of the descaling liquid by the residual cleaning water in the water passage is avoided, and the descaling effect is effectively improved.