In order to investigate the influence law of pump chamber structure parameters on the performance of piezoelectric gas diaphragm pump, a pump chamber structure of piezoelectric gas diaphragm pump was designed, Firstly, the structural design and working principle of the pump chamber are briefly described, and the expression of the relationship between the airflow velocity at the outlet of the pump chamber is derived, and the relationship between the height of the pump chamber and the diameter of the air hole on the instantaneous air pressure, airflow velocity and gas flow in the chamber is obtained through simulation, Finally, a pump cavity is machined and applied to a piezoelectric gas diaphragm pump, and experimental tests and the theoretical analysis are conducted, and experimental results are consistent with the theoretical analysis, The output flow rate decreases with increasing cavity height and increases with increasing orifice diameter, Provides a theoretical reference for the design of the cavity of the piezoelectric gas micropump,