The invention discloses a washing machine and a washing method for automatically calculating washing frequency according to an electric energy value of an energy storage power supply, and relates to the washing machine in household appliances. The washing machine comprises a washing machine master control unit, and an operating panel, a display unit and an inverter switching unit which are connected with the washing machine master control unit, wherein the inverter switching unit is connected with an energy storage power supply and an electric network power supply respectively; and the washing machine master control unit is connected with an energy storage power supply management unit, controls the use of the energy storage power supply by a current washing program through the energy storage power supply management module and outputs the use information through the display unit. Through the washing machine and the washing method, a user can clearly know whether the current energy storage power supply can finish the selected washing program, and the washing machine can automatically switch between various energy sources, so that normal operation of the washing program can also be ensured when the electric quantity of the currently used energy storage power supply is insufficient, the energy storage power supply is protected, and the life of the energy storage power supply is prolonged.