Sterilization method of water purifying and drinking machine

The invention discloses a sterilization method of a water purifying and drinking machine, the water purifying and drinking machine comprises a cold tank, a first water pump, a hot tank and a water outlet assembly, the cold tank is connected with a water inlet pipeline provided with a water leakage prevention assembly, the water outlet assembly comprises a water outlet solenoid valve and a water outlet nozzle, and an input port of the water outlet solenoid valve is respectively communicated with an output port of the cold tank and an output port of the hot tank; the cold tank is connected with the hot tank through a first water pump; the sterilization method of the water purifying and drinking machine comprises the following steps: plugging the water outlet nozzle to enable the cold tank, the first water pump, the hot tank and the water outlet electromagnetic valve to form a complete closed pipeline; starting a pretreatment module, performing hot water circulation sterilization pretreatment, and closing a conv