Diamond bead wire saw cutting technology for coal seams is an effective approach for relieving pressure and enhancing permeability by forming internal slits within a coal seam. However, the current lack of solid theoretical guidance for cutting force models in loaded coal bodies makes it difficult to accurately predict cutting forces under underground conditions. This study established a three-dimensional cutting force model for wire saw cutting of loaded coal bodies. At the same time, comparative experiments were conducted using a self-developed experimental apparatus for cutting loaded coal with a wire saw. The research findings indicate that, during wire saw cutting of loaded coal bodies, increasing the cutting depth of the cutting force of a single abrasive grain by changing the load on both sides of the coal body changes the removal patterns of abrasive particles at different orientations on a single bead. This leads to a shift from plastic deformation to brittle deformation while widening the cutting contact area on both sides of the wire saw. The interaction of these aspects changes the cutting force exerted by the wire saw on loaded coal bodies. The experimental results revealed that under high-load conditions, the cutting force on the coal further increased during wire saw cutting. This suggests that the expansion of the cutting range plays a more significant role in increasing the cutting force than does the decrease resulting from changes in removal mode. These findings offer valuable theoretical insights for the process design of wire saw coal cutting technology.