A successive iteration method has been developed to investigate the MHD equilibrium of high-current plasma in an ℓ > 1 toroidal-helical configuration of large aspect ratio. In this scheme, helical and toroidal effects are treated as perturbations. The order of perturbation determines possible Fourier mode numbers, and the equilibrium configuration can be expressed by a small number of Fourier terms. The differential equations for the Fourier coefficients have been studied and solved numerically up to the toroidal-helical coupling effect for OHTE configurations.