Under the effect of “three highs and one disturbance”, the surrounding rock of deep coal mine roadways is prone to continuous large deformation, coal and rock softening and poor permeability. In this study, acrylamide (AM) monomer was used to in-situ polymerize and modify sulfoaluminate cement grouting material (SCGM), and the effect of AM dosage on the slurry property, mechanical properties and microstructure of SCGM was systematically studied, and its toughening mechanism was discussed. The results show that AM can improve the fluidity of slurry, but when the AM dosage reaches 30% (mass fraction), the initial setting time of slurry is greater than 50 min, and the maximum reaction temperature is greater than 80.0 ℃, which affects the self-sealing effect and safety of slurry. In-situ polymerization modification of AM can enhance the bonding strength between stone body and coal body, and significantly improve SCGM toughness. When the AM dosage is 20%, compared with control group, the coal bonding strength at 28 d increases by 20.6%, the relative compressive relative toughness at 28 d increases by 35.4 times, and the tensile relative toughness at 28 d increases by 15.2 times. The field application results of the 2715 lower roadway in Cheji Coal Mine show that the SCGM modified by in-situ polymerization of AM with a dosage of 20% has a better effect on improving the integrity and stability of coal rock, and the shrinkage rate of roadway after excavation for 100 d is controlled within 2%. This study provides a high-toughness material for the field of deep coal mine roadway surrounding rock grouting reinforcement, which is of great significance for the stability and safety guarantee of deep coal mine roadway.