The invention discloses a water and electricity linkage device and a method adopted by the water and electricity linkage device. The water and electricity linkage device comprises a heating cavity and a water storage tank, wherein the heating cavity communicates with the water storage tank through a water through pipe, an inner cup and an electric heating pipe are arranged in the heating cavity from top to bottom, and the inner cup is provided with a water outlet extending out of the heating cavity, and an opening is formed in the top of the inner cup; a water inlet of the water storage tank is connected with a water inlet pipe, the water storage tank is provided with three water level probes extending into the water storage tank, the length of the No.1 probe is greater than the length of the No.2 probe, and the length of the No.2 probe is greater than the length of the No.3 probe; the water level of the water storage tank is level with the water level of the heating cavity. The water and electricity linkage device has the beneficial effects that through the recycling of the steam heat energy, the energy consumption is reduced; the water level rises as boiling water is in a boiling state, then the boiling water enters the inner cup to be taken as drinking water, and thus the drinking water hygiene is improved; the safety of each component of the device is monitored in time, and alarming and reminding are made aiming at the relevant problems; the water inlet, heating and heat preservation are intelligently controlled, the timed startup and shutdown function is provided, and therefore, the operation is convenient and rapid; the heating effect is rapidly improved, and the energy loss is reduced.