Due to the requirements of manufacturing accuracy and surface quality consistency, which will influence the dynamic properties and service cycle of aircraft engines, the high-precision material removal depth model is urgently needed for robot automatic grinding aviation blade system. This research developed a novel material removal depth (MRD) model to ensure quantitative grinding depth point by point for robot automatic grinding aviation blade. Firstly, the relationship between contact stress and contact force is developed based on simulation and theoretical derivation, and the contact contour is further investigated by the experiments. Then, the nonlinear material removal depth model is established to predict grinding depth according to Preston equation. Meanwhile, multiple linear regression method is introduced to analyze parameters of material removal depth model. The previous researches show that grinding parameters have strong correlation with MRD, especially for the non-negligible contact force consideration. Therefore, the non-uniform material removal with variable contact force strategy is developed according to the proposed model, and the proposed strategy is applied to the robot automatic grinding aviation blade system to achieve the quantitative grinding depth point by point on the aviation blade surface. The practice experiments further prove that the developed strategy is feasible and effective. Comparing the predicted and experimental MRD, the maximum errors and average relative errors are respectively 9.21% and 4.68%, when the aviation blade is ground by the proposed material removal strategy. Simultaneously, the experimental results tend to produce much better surface roughness with uniform surface texture which satisfies grinding requirements.