The utility model discloses a steam electric iron comprising a flatiron bottom board, a steam chamber and a thermoregulation bottom board of independent control, and a temperature automatic controlling circuit, having the characteristics that the independent controlling steam chamber and the independent controlling thermoregulation bottom board are controlled by the temperature automatic controlling circuit which is connected with two heating elements heating alternatively. A heating element with heating priority is provided inside the steam chamber, a temperature sensor is arranged on the steam chamber, a temperature sensor is arranged on the thermoregulation bottom board. The temperature automatic controlling circuit comprises a first heating element, a first temperature sensor connected with the first heating element, a second heating element, a second temperature sensor connected with the second heating element, an interlocking relay connected with the first heating element and the second heating element, a relay connected with the interlocking relay and a MCU connected with the first temperature sensor and the second temperature sensor. The utility model employs the technical project thereby two heating elements are controlled by the temperature automatic controlling circuit on power and heat alternatively, the whole electric iron power reaches above 4800W.