The purpose of the paper is the problem of determination of parameters of hyperfine wire drawing process of biocompatible magnesium alloys. The originality of the considered alloys is the intergranular fracture mechanism associated with small strains (0.07–0.09) in macro-scale. It was proven that the material state just before appearance of the meso-cracks is the optimal state of material from the point of view of the restoration of the plasticity by annealing. The forecasting of this material state during drawing process requires the development of the model of intergranular fracture. In this case, new BEM model of the cracks initiation in meso-scale is proposed. The in situ tests, which allowed observation of the microstructure during deformation, are used for the calibration and validation of the present model. The empirical parameters of the fracture model in micro-scale for MgCa0.8 and Ax30 magnesium alloys are obtained using tensile and share tests. The developed model was implemented to the Drawing 2d software. The results of meso-scale simulation were verified by using the experimental drawing process of the hyperfine wires (diameter 70 µm) according to developed technology.