Abstract: To further research the structure principle and the operation stability of the degrees of freedom parallel hydraulic support, based on the theory of parallel topological structure, we demonstrate that the hydraulic support has the capacity of yield and pressure relief in x, y, z direction; secondly, by establishing mechanical model of large angle working condition, we demonstrate the stability of hydraulic support under the condition of large dip angle; finally, we carry out static simulation experiments on hydraulic support under different working conditions by using Ansys Workbench software. The results show that the hydraulic support has good stability, adaptability and stronger twisting resistance in large dip angle, and parts meet the requirements of job safety.