During metal milling, top burrs will inevitably appear on the edge of the workpiece, which seriously reduces the edge quality and assembly accuracy of the workpiece, thereby reducing the service performance of the product. This study innovatively proposes an ice boundary constraint (IBC) method to avoid top burrs formation during cutting. First, the formation mechanism of the top burrs is analyzed, and the principle of IBC is interpreted. Then, an analytical model is established to realize the cutting analysis, obtain the stress distribution during cutting, and explore the plastic deformation process of the workpiece edge, thus revealing top burrs suppression mechanism and predicting top burrs height. Afterwards, based on the proposed analytical model, finite element method (FEM) is used to simulate the stress distribution at the top edge to verify the stress analysis results of the analytical model. Finally, the effectiveness of IBC method and the prediction accuracy of the analytical model are verified by aluminum alloy 2024 (AA2024) milling experiments. The experimental results show that IBC method can reduce the top burrs height by 54.62% on average, and the percentage of average prediction error of the analytical model is limited to 16.66%. Moreover, the milling experiments of carbon steel and aluminum alloy 6061 (AA6061) are carried out under the same process parameters, and the results show that IBC method can realize the suppression of top burrs of different materials. This study can provide valuable theoretical and practical reference for the minimization of burrs formation during cutting.