The invention provides a heat storage water tank, and a control method and control system of the heat storage water tank. The heat storage water tank comprises a casing, a cavity, at least two electric heating tubes, at least two temperature sensors, at least two heating coils, at least one floor heating heat exchange coil and at least one controller, wherein the casing is provided with a water inlet, a water outlet and a sewage draining exit; the cavity is formed by the casing; water is contained inside the cavity; the electric heating tubes are arranged on the casing and extend into the interior of the cavity; the temperature sensors are arranged on the casing and extend into the interior of the cavity; the heating coils are arranged in the casing; the floor heating heat exchange coil is arranged inside the casing; the controller is arranged on the casing. Through the technical scheme, the heat storage water tank achieves the use requirement on all-weather different water temperature in the condition that the heat storage water tank is not affected by outer circumstance temperature condition and the situation of heating source, can not only provide floor heating low-temperature water, but also provide domestic high-temperature hot water, and meanwhile is helpful to improve the heat collecting efficiency and reduce the heat loss, thereby achieving the purpose of energy saving.