The working resistance of the hydraulic support is the final resistance when the hydraulic support is compressed, and it is the acting force along the axial direction of the oil cylinder when the hydraulic support works. Under the constant resistance state of the hydraulic support, the overflow of the safety valve will continue to sink, and the overflow of the safety valve will continue to sink when the hydraulic support presses the constant resistance state of the support in the bearing stage. The maximum load of hydraulic support column and support in the bearing stage is called the maximum working resistance.

Working resistance = support strength x support area

Hydraulic support is the supporting equipment of fully mechanized mining face, its main function is to support the roof of stope, maintain safe working space and promote the mining and transportation equipment of working face. In the working process, the hydraulic support should not only support the roof reliably, but also move forward with the advance of the working face. It is required that the hydraulic support must have four basic actions: lifting, lowering, pushing and moving. These actions are realized by using the high-pressure liquid supplied by emulsion pump station to control the expansion and contraction of columns and jacks through various valves. According to its structural characteristics and interaction with surrounding rock, hydraulic supports are generally divided into three categories, namely, support type, shield type and support shield type. Simply put, it is used to support the coal mine roof and prevent it from collapsing.