<p>Calcium fluoride crystals play an irreplaceable role in practical applications and scientific theoretical research due to their physical and chemical properties, excellent optical properties, and structural characteristics. In order to obtain the surface of the calcium fluoride crystal with low damage, this paper expounds the basic theory of magnetohydrodynamics and the principle of magnetorheological machining removal, combining numerical simulation and experimental analysis of the role of different polishing speed, abrasive grain concentration, excitation gap on the calcium fluoride crystal surface of the wall shear force, and dynamic pressure distribution, to explore the influence of the process parameters. The orthogonal test method was used to study the process of abrasive flow machining of transmission gears, and finally the polishing speed was analyzed as the factor with the most significant influence among the three factors. The surface roughness was improved from 0.036 to 0.029&#xa0;µm on the final calcium fluoride crystalline material, resulting in a desirable flat surface. The feasibility of the magnetorheological polishing technique for ultra-precision machining of calcium fluoride crystals is verified. It provides technical support for the actual magnetorheological polishing technology for processing calcium fluoride crystal materials.</p>