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The loosening and fracture of the blade root bolt, a crucial link between the blade and hub, significantly affect the wind turbine's safe operation. To address this issue, the load redistribution after loosening and fracture of the blade root bolts is considered first. The theoretical model of axial force calculation of the blade root bolts is then deduced and verified through tests. Subsequently, a finite element model of the blade root bolt connection structure is established, and its effectiveness is analyzed. Finally, based on the finite element model, the effects of the preload force, the number of loosened or fractured, and the area of loosened or fractured on the loading characteristics of blade root bolts are investigated. Results show that when the preload force of the loosened blade root bolts is not zero, its axial stress variation law is the same as its preload force variation law. When the preload force is zero, the axial stress of the blade root bolts with zero preload force increases, whereas the axial stress of the non-loosened blade root bolts decreases. Exceeding the material's ultimate strength causes the blade root bolt to fracture. The axial stress in the loosened blade root bolts around the center of the fractured decreases, and the magnitude of the axial stresses of the surrounding non-loosened blade root bolts increases and then decreases along the fractured center to both sides. The findings can offer theoretical guidance for predicting the fatigue life of blade root bolts and their online monitoring. [ABSTRACT FROM AUTHOR]