Optical observations by the HST have shown a fantastic 3-ring structure in the circumstellar space of the SN 1987A. We attempt to reproduce the 3-ring structure from an MHD simulation which takes into account the wind-wind interaction between the slow, magnetized stellar wind generated while the progenitor was a red supergiant (RSG) and the subsequent fast stellar wind ejected from the same star after it had evolved into the blue supergiant (BSG). An important assumption in the simulation is that both the RSG and BSG winds have toroidal magnetic field and coronal holes. The simulation shows that the magnetic pinch effect is essential for the formation of the equatorial ring and that the amplification of initial density asymmetry by the effect of the dynamical interaction is responsible for the formation of two outer rings.