The air operated double diaphragm pump relies on the air compressor to input the compressed air into the air distribution valve of the diaphragm pump to drive the connecting shaft in the intermediate body of the diaphragm pump to drive the diaphragm pump diaphragm in the medium chamber of the diaphragm pump body to do lateral stretching movement to achieve self-priming fluid. Positive displacement reciprocating pump. In the two symmetrical working chambers of the pump, an elastic diaphragm is installed in each, and the connecting rod integrates the two diaphragms.