1. As the operating pressure of the pneumatic system is generally in the range of 0.2-1.0Mpa, the cylinder cannot be used as a high-power power element.  The hydraulic cylinder can be used as a relatively high-power component and a hydraulic system can be used.

2. From the perspective of medium, air is inexhaustible and there is no cost or supply difficulty. Used gas is directly discharged into the atmosphere, which is convenient to handle and will not pollute, while hydraulic oil is the opposite.

3, the air viscosity is small, the resistance is less than the hydraulic oil.

4. However, the compression rate of air is much higher than that of hydraulic oil, so its working stability and response are far from satisfactory.  Hydraulic cylinder is the most important actuator in hydraulic system. It converts hydraulic energy into mechanical energy and cooperates with various transmission mechanisms to complete various mechanical movements.  The hydraulic cylinder has the characteristics of simple structure, large output force, stable and reliable performance, convenient use and maintenance, wide application range, etc.