The cubic law of radiation flow was corrected, and the mechanical properties and hydraulic characteristics of fracture were studied. High hydraulic head shear percolation experiments at different constant normal pressures and shear rates were performed. It was found that the peak shear strength increased first and then decreased with the increase of shear rate. The linear coefficient A and the nonlinear coefficient B exhibit a tendency to decrease as the shear displacement first increases and a decrease in the stable value smaller than the value before shear failure. However, the coefficient B is five orders of magnitude larger than the coefficient A, and the magnitude of the change is larger. The critical Reynolds number increases after shear failure to a value greater than that before shear failure, and the flow state will become better. In addition, the hydraulic properties during shearing also show a similar trend to mechanical properties.