Based on the analytic solution of hydromagnetic flow due to a rotrating disk, both velocity field and effective segregation coefficient Keff of solute in silicon melt in terms of one dimensional model were calculated under actions of various axial magnetic field strength. Results of computer simulation are presented graphically. It is found that not only the magnitudes of velocity components are strongly suppressed by magnetic field, but also the Keff of solute increases as the magnetic field increases with given rotational rate, finally tends to a constant within some definite regions of magnetic field. In addition, it is also found that the Keff is strongly dependent on the diffusion coefficient of solute.