The propagation properties of electromagnetic waves excited by helicon antenna with a parabolic radial electron density distribution in an external magnetic field were studied. Maxwell equations are numerically solved using the linear disturbance wave assumption to obtain energy distribution, when the magnetic intensity changes from 80 to 800 G. The radial electromagnetic wave and energy deposition intensity distributions were obtained. Results show that when magnetic intensity grows, the helicon wave is little damped and it can propagate into the bulk plasma; Trivelpiece-Gould (TG) wave is heavily damped at plasma-vacuum interface; the main energy absorption region moves towards the boundary gradually. When the magnetic intensity is lower than 100 G, the TG wave can propagate into the bulk plasma, and the plasma radial energy distribution is relatively uniform.