We represent results of numerical simulation of magnetorotational (MR) instability which develops in MR core-collapsed supernova explosion. The MR instability leads to the exponential growth of all components of the magnetic field. It significantly reduce the time for the development of MR exlosion. The MR instability is of Tayler type with rotation. The maximal values of magnetic field found in our simulations is 10(16) Gauss.