The invention discloses a miniature electromagnetic valve based on precision instruments. The miniature electromagnetic valve comprises an electromagnet and a valve seat arranged below the electromagnet. An elastic part is arranged on the inner ring of an electromagnet coil, one end of the elastic part is fixedly arranged on the electromagnet, the other end of the elastic part abuts against an iron core of the electromagnet, and the lower end of the iron core is fixedly connected with a valve body diaphragm. The upper surface of the valve seat is provided with a sealing groove relative to the valve body diaphragm, a first passageway and a second passageway are formed in the valve seat and communicated through the sealing groove, and the valve seat and the valve body diaphragm are both made of PFA materials. According to the change of a magnetic field during power-on and power-off of the coil, the iron core drives the valve body diaphragm to move up and down, control over conduction of a medium is achieved by opening and closing the sealing groove, and the sealing performance is good. The problem that the biological medium is attached to passageways of an electromagnetic valve to cause blockage of the passageways can be avoided through the valve seat and the valve body diaphragm made of the PFA materials.