The m=2/n=1 tearing mode instability with local driving helical current was studied by using the reduced magnetohydrodynamics (RMHD) simulation method in the large-aspect-ratio Tokamak. The effects of different characteristics of driving helical current, such as intensity, radial deposition width and starting deposition time were analyzed. The results indicate that the driving helical current with larger intensity and more focused deposition width has a better suppression effect on the tearing modes. But destabilizing effect, called "flip" inst...