Intelligent closestool with low-power large-flow flushing device and using method

The invention discloses an intelligent closestool with a low-power large-flow flushing device. The intelligent closestool comprises a closestool body and a flushing device arranged on the closestool body and used for flushing the private part of a human body, the flushing device comprises a preheating barrel body, a heat-conducting medium is injected into the preheating barrel body, a preheating pipe immersed in a heat-conducting medium is arranged in the preheating barrel body, a preheating heating device for heating the heat-conducting medium to preheat water flowing through the preheating pipe is arranged in the preheating barrel body, the water inlet end of the preheating pipe is connected with an external water source, and the water outlet end of the preheating pipe is sequentially connected with an instant heating device for instantly heating preheated water flow to a preset temperature and a water outlet pipeline which extends into the inner cavity of the closestool body and isused for flushing the pri