Also known as an air operated diaphragm pump reciprocating pumps of a kind, with a flexible membrane, corrosion-resistant rubber or elastic metal sheet to separate the pump into two parts that do not communicate with each other, respectively, the liquid being conveyed and the area where the live column exists. In this way, the column does not come into contact with the conveyed liquid. The reciprocating motion of the column is transmitted to the diaphragm through the medium on the same side, so that the diaphragm also makes reciprocating motion, thus realizing the suction and discharge of the conveyed liquid through the spherical valve. The only part of the diaphragm pump that is in contact with the conveyed liquid is the spherical valve, which is easy to be made in a form that is not infringed by the liquid. In industrial production, diaphragm pumps are mainly used to transport corrosive liquids or liquids containing suspended solids.