<p>Titanium alloy is widely utilized in the manufacturing of crucial components for aerospace and other industries due to its excellent physical and mechanical properties. Flexible abrasive disc grinding provides significant advantages in titanium alloy machining, yet the interaction between the abrasive disc and the titanium alloy surface is extremely complex. This study aims to reveal the mechanism of the flexible abrasive disc grinding process through the study of the interaction of multi-grains and the material removal process. Specifically, the motion trajectory of a single grain and the contact area formula on the workpiece surface were derived. Additionally, a simulation model for multi-grains grinding of TC17 titanium alloy was established. The study further explores the contribution of individual grains to the total grinding force within the multi-grains model, as well as the material removal mechanism in flexible abrasive disc grinding. The simulation results indicated that the interaction among the abrasive grains and the surface morphology of the contact area significantly impacts the grinding force. The actual count of effective abrasive grains participating in the grinding process was fewer than that predicted by geometric calculation. The grinding tracks display a crescent shape, and as the distance from the grinding center increases, their depth and width decrease. When compared to the experimental data, the prediction error of the simulation model for the normal grinding force was 6.3%, whereas the errors for the depth and width of the grinding track remained under 14.0%, thereby validating the accuracy of the multi-grains grinding model.</p>