The electrical and optical properties of ion tracks in PS and PE irradiated with high energy heavy ions were investigated by Terahertz Time-Domain Spectroscopy(THz-TDS). It was found that the refractive index and absorption coefficient in THz frequency range of ion track in irradiated PS were larger than those of virgin PS，while the refractive index of ion track in irradiated PE lower than that of virgin PE, and the absorption coefficient of track in irradiated PE larger than that of virgin PE. The different change trends of refractive index of ion track in PS and PE were attributed to the polymer structures. The optical constants of ion track were extracted using Effective Medium Theory(EMT). The DC resistivity and carrier mobility of ion track were obtained by analyzing the results with Drude-Lorentz theory. The difference of the electrical constants obtained from this method and contacting measurements was attributed to the discontinuity of the energy density deposited by the ions. The THz-TDS results could be related to the electrical properties of ion track with the higher energy density.