Pre-drainage cold water circulation system and method based on coupling combination of return pipe and thermistor

The invention relates to a pre-drainage cold water circulation system and method based on coupling combination of a return pipe and a thermistor. The pre-drainage cold water circulation system comprises a water storage device and a water inlet pipe, and the water inlet pipe is provided with a vertical embedded pipe section arranged in the water storage device in a penetrating manner, and a cold water outflow pipe and a cold water return pipe which communicate with the water storage device are arranged on the lower part and the upper part of the vertical embedded pipe section respectively; a first switch element is arranged on the cold water outflow pipe, and a second switch element is arranged at the lower end of the vertical embedded pipe section; and a first temperature sensor is arranged on the vertical embedded pipe section located above the cold water outflow pipe, and a second temperature sensor is arranged on the vertical embedded pipe section located between the cold water outflow pipe and the cold wa