Indoor shearing device and method for deteriorated fractured rock mass structural plane under complex conditions

The invention provides an indoor shearing device and method for a deteriorated broken rock mass structural plane under complex conditions, the indoor shearing device comprises a support, a lower shearing box, an upper shearing box, a flexible sealing ring, a shearing assembly and a normal pressurizing assembly, the lower shearing box is movably installed on the support, and the upper shearing box is in butt joint with the lower shearing box; a flexible sealing ring is arranged at the joint of the lower shearing box and the upper shearing box; and the shearing assembly comprises a hydraulic cylinder, a connecting ring, a sliding frame and a push rod. By rotating the connecting ring, the push rod is parallel to the central axis of the hydraulic cylinder or forms an acute angle with the central axis of the hydraulic cylinder, so that the connecting ring is pushed to translate or twist when the hydraulic cylinder acts, the lower shear box performs direct shear or torsional shear on the sample, and the mechanical