Abstract: Aiming at problem that single attitude measurement of hydraulic support can not fully reflect comprehensive state of hydraulic support, and can not realize accurate perception of supporting state of hydraulic support, taking two column shield hydraulic support as an example, based on three-dimensional space stress model of hydraulic support, supporting state classification and stability of hydraulic support are analyzed from two aspects of spatial geometric state and structural load, and it is pointed out that the key influencing parameters of hydraulic support are inclination angle, pressure and pin force.When hydraulic support and surrounding rock are in uncoupled state, geometric instability is easy to occur: the geometric equilibrium equation is constructed, and the height of gravity center and the dip angle of working face are the key factors affecting the stability; A method of determining the center of gravity position of hydraulic support with three inclination angles of top beam, base and front link is put forward, and the state perception is realized by using dual axis inclination sensor.When hydraulic support and surrounding rock are in coupling state, bearing instability is easy to occur: accurate solution equation of the resultant force point of the hydraulic support is constructed, the state perception of the top beam and the shield beam is realized by the force measuring pin shaft, and the bearing instability type is determined according to the balance zone theory.