Grouting test device and test method under hydraulic shearing critical condition

The invention discloses a grouting test device and method under hydraulic shear critical conditions, the grouting test device comprises a sample, an axial pressurization system, a confining pressure loading system, a water injection circulation system and a grouting circulation system, the sample is provided with a fault surface, and a water injection hole and a grouting hole which penetrate through the fault surface are formed in the sample; the axial pressurizing system is used for applying axial pressure to the sample; the confining pressure loading system is used for applying confining pressure to the sample; the water injection circulating system is communicated with the water injection hole so as to apply water injection pressure to the sample and simulate a hydraulic shear test; the grouting circulating system is communicated with the grouting hole so as to apply grouting pressure to the sample and simulate a grout injection test; the grouting process of the fault fracture zone under the condition of h