Abstract: Disclosed are an underground engineering rock mass shear simulation test device, a test method and a test machine. The test method includes: setting different test conditions by a controller to perform cyclic shear test at high temperature, fracture shear seepage test, granite uniaxial compression test at high temperature and granite fracture shear test under constant normal stiffness boundary conditions at room temperature. The electric heating wire assembly, the fan assembly and the environmental box are combined to flexibly and uniformly heat the samples placed in the upper shear box and the lower shear box. In terms of shear-seepage test, this scheme proposes a second sample placing mechanism that realizes sealing through sealing capsule and sealing capsule pressing plate. It realizes stable sealing and facilitates monitoring and debugging of seepage parameters.