Abstract: Aiming at the contradiction between the automatic control logic,the liquid supply system and the working speed of the hydraulic supportat the fully-mechanized mining face,the hydraulic system of the hydraulic support is analyzed by modularization and parameterization,taking into account the layouts of the inlet and return lines.Modeling and calculation are conducted on the hydraulic system of the support from the steady-state characteristics and transient characteristics respectively.Decoupling analysis is conducted on the pipeline pressure and flow during multiple actions in the process of following the shearer to obtain the law of pressure change with time and the iterative model through deduction in the transient and steady-state processes.The results show that the pressure change of the hydraulic cylinder is mainly related to the inlet pressure and the return pressure,the quadratic relationship of time t.According to the above derivation formula,the actual parameters of working face of Bayangaole Mine are used to evaluate the pressure distribution characteristics .The pressure dynamic data measurement of the hydraulic cylinders under different liquid supply conditions is completed,which verifies the scientificity and effectiveness of the theoretical analysis model.The results show that the system back pressure mainly affects the steady state process,has less impact on transient processes.