The invention provides an E type transformer and a safety alarm apparatus, and relates to the technical field of the transformer. The E type transformer comprises a primary coil, a secondary coil and an E type iron core; the E type iron core comprises a transverse magnetic core and three longitudinal magnetic cores; the three longitudinal magnetic cores are arranged at the two ends and the middle position of the transverse magnetic core respectively; an adjustment rotary knob is arranged on the end part, connected with the transverse magnetic core, of the longitudinal magnetic core arranged in the middle position; by rotating the adjustment rotary knob, the longitudinal magnetic core can be extended and retracted in the extension direction so as to adjust the number of turns of the coil which is wound around the longitudinal magnetic core; and the magnetic core of the E type iron core is wound with the primary coil and the secondary coil separately. By virtue of the E type transformer provided by the invention, the winding of the transformer can be changed flexibly, so as to change the alternating current output voltage and satisfy requirement of a circuit on variable voltages.