The core feature of a diaphragm compressor is its use of a flexible diaphragm to completely isolate the gas from the compressor's mechanical parts, ensuring high gas purity and preventing leakage and contamination. Therefore, it is suitable for compressing high-purity, rare, valuable, flammable, explosive, toxic, harmful, corrosive, and high-pressure gases.

The working principle of a diaphragm compressor is based on an energy transfer chain of "hydraulic drive - diaphragm deformation - gas compression." The working cycle of a diaphragm compressor includes four stages: intake, compression, exhaust, and reset. During intake, the diaphragm moves towards the hydraulic chamber, increasing the gas chamber volume and creating a negative pressure, drawing gas in through the intake valve. During compression, the diaphragm moves in the opposite direction, decreasing the gas chamber volume, compressing the gas, and gradually increasing the pressure. During exhaust, when the gas pressure reaches the set value, the exhaust valve opens, and the compressed gas is discharged. During reset, the diaphragm moves back towards the hydraulic chamber, preparing for the next cycle. In each working cycle, hydraulic oil needs to be replenished to the oil chamber by an oil pump to maintain the required oil pressure.

Because the ratio of the working volume surface area of ​​the cylinder to the cylinder volume of a diaphragm compressor is much larger than that of a reciprocating piston compressor, the compression of the gas is close to an isothermal process, so the pressure ratio of each stage can be as high as 25.