In order to use polyurethane grouting materials more safely and scientifically, the paper explains key problems when polyurethane reinforcement materials are used. The influence factors of the bond performance of reinforcement materials are analyzed and the effects of polyether polyols and isocyanate index on cohesive strength of grouting materials are explored. By adjusting the polyether and isocyanate index, the bonding strength of the materials is up to 14.1 MPa, and it has the ideal matching fault tolerance. The engineering practice indicates that the reinforcement materials still reacts normally when the ratio is misaligned by 20%, and the integrity and bearing capacity of the crushed coal body are improved significantly after reinforcement.
