In order to study the influence of rock fragmentation on the bearing capacity of rock-socketed pile, a concrete rock-shear model considering rock fragmentation was established using statistical theory. The calculation results of the model were compared with the experimental results to verify the accuracy of the model. Using a concrete rock shear model considering rock fragmentation and the load transfer mechanism of rock-socketed pile, a load transfer equation of rock socketed pile considering rock fragmentation was established and solved using the Runge-Kutta method. The calculation results of the equation were compared with the results of on-site static load experiments, which verified the accuracy of the equation. The research results indicate that it is feasible to establish a mechanical model for rock fragmentation through statistical theory. The load transfer equation of rock socketed pile considering rock fragmentation is consistent with the results of on-site static load experiments, which can describe the yield deformation stage and strain softening stage of the pile-rock relative displacement-pile side friction curve. The parameter sensitivity research was conducted, and the influence of rock fragmentation on the concrete-rock shear mechanism and rock-socketed pile bearing mechanism was conducted in-depth analysis.