The invention discloses electromagnet type transverse magnetic field heat treatment equipment comprising a heating furnace and an electromagnet, wherein the magnetic field direction generated by the electromagnet is parallel to the vertical direction of the heating furnace; the heating furnace comprises a furnace casing and a hearth formed by the furnace casing; and a heating element is arranged at the inner side of a furnace wall. In the process of preparing a permanent magnet iron core by using the equipment, an iron core to be treated is placed in the hearth of the transverse magnetic field heat treatment equipment; the temperature in the hearth is adjusted in the range of +/-10 DEG C of the Curie temperature of the iron core to be treated by using the heating element; a magnetic filedis applied to the direction vertical to the circumference of the iron core to be treated by using the magnet; and the magnetic filed intensity at the central point of the hearth is 0-800Gs and can becontinuously adjusted. The process and the equipment can be used for treating crystalline or amorphous magnetically soft alloy iron cores, the Curie temperatures of which are lower than 600 DEG C; the magnetic filed intensity in the center of the hearth is as high as 800Gs; and the invention has the advantages of low construction cost, high production efficiency as well as low cost and energy consumption.