Abstract: A numerical code has been established for solving self-consistent equilibrium equation and calculating the dependence of the tearing mode on the current density profile. The external belieal field effect is included in it.The dynamic alternating direction implicit method is applied to speed up the convergence of solution of equilibrium equation and three-point difference secheme is taken to solve the singular boundary value problem with two singular points.

Key words: tearing mode, self-consistent equilibrium equation, singular boundary value problem, numerical solution