<p>Compared with conventional polishing methods for curved surfaces, constant-pressure polishing can achieve more uniform material removal by continuously adjusting the polishing force to accommodate curvature variations within the contact region. However, the theoretical description of the constant-pressure polishing process is still incomplete, which limits its predictive capability and practical application. To address this issue, this study develops a deterministic polishing model for constant-pressure polishing based on Hertzian contact theory, in which the deformation behavior of the polishing head during the polishing process is explicitly characterized. The proposed model establishes the mapping relationship between key polishing parameters and the workpiece curvature, thereby providing theoretical guidance for process planning and parameter optimization in constant-pressure polishing. Furthermore, by incorporating the Preston equation, the model enables theoretical prediction of the polished surface profile and material removal distribution. The research results indicate that constant-pressure polishing has better adaptability when processing curved surfaces and can achieve a more uniform removal effect than traditional polishing methods. After calculating the correlation coefficient in the Hertz contact model, the prediction error of the material removal curve was reduced to approximately 10%, further verifying the effectiveness of the proposed method. Overall, this work improves the theoretical framework of constant-pressure polishing and provides a useful basis for deterministic polishing of complex curved surfaces. The proposed model is expected to support further optimization of polishing parameter selection and to promote the application of constant-pressure polishing in the high-precision manufacturing of advanced optical and engineering components.</p>