Abstract: The invention discloses a steam hair straightener, comprising an upper handle and an upper cover forming the upper part, and a lower handle and a lower cover forming the lower part, wherein the upper handle and the upper cover are assembled and fixed by screws, and a first installation cavity is formed there between; the lower handle and the lower cover are also assembled and fixed by screws, and a second installation cavity is formed there between; the inside of the first installation cavity is equipped with an upper heating plate, a hot steam device, a water tank and a water pump; the second installation cavity is equipped with a lower heating plate, an infrared device, a function control board, and a 360° rotating power cord; the hot steam device is installed on the upper heating plate.