Abstract: In order to solve the anchoring defects problem in underground roadway bolting process, this paper establishes an mechanical model of bolts with anchoring defects based on elastic theory and analyzes it, then deduces the axial stress and shear stress distribution of bolts with one anchoring defect by pull-out load. The paper studies the influence factors of the length and position of the anchoring defects, and obtains the influence laws of the anchoring defects on the bolt anchoring load.