Abstract: To study the mechanical properties of grouting material under cyclic loading and unloading, rock mechanics tests of constant confining pressure, cyclic loading and unloading axial pressure were carried out on rock slurry using RMT-150B rock mechanics testing machine, and the strength and deformation characteristics of grouting material were analyzed. The results show that: the area of plastic hysteresis loop increases with the increase of axial pressure of rock slurry; the circulation under low stress state will make the rock slurry denser, and the strength of the grouting material under loading and unloading is higher than that the conventional tri-axial compression test, failure occurs when the critical strength is exceeded, and the strength decreases with the increase of rock particle size; under cyclic loading and unloading, the grouting material is mainly shear failure, and the low confining pressure and coarse particle size are more likely to form obvious shear bands. Based on the research results, the key techniques of soft rock grouting reinforcement for increasing bolt pre-stress and reinforcing grouting effect are proposed.