The invention discloses a bidirectional rotary electromagnet and retention mechanism on an electromagnetic valve; the bidirectional rotary electromagnet and retention mechanism comprise a bidirectional rotary electromagnet and a retention mechanism; a first coil component is arranged around a first iron stopper, a first shell is mounted at the outer end of the first coil component, one end of thefirst iron stopper and one end of a second iron stopper are provided with a first armature and a second armature respectively, a magnetism-shielding ring is mounted between a fourth iron stopper and athird iron stopper, the retention mechanism comprises a positioning plate, a lower positioning pin, a retention spring, a retention rod and an upper positioning pin, and the retention rod and the retention spring are integrally fixed to the positioning plate through the upper positioning pin and the lower positioning pin. The electromagnetic valve with the bidirectional rotary electromagnet and retention mechanism can be retained in operating state by the electromagnet without continuous electrification, a reversing function is provided, the service life of the electromagnet is greatly extended, and operational reliability of the electromagnetic valve is guaranteed.