The authors present a one-dimensional calculation model of H+3, and the time-dependent wavefunction was obtained by the symmetric split-operator method. The authors investigated the high-order harmonic generation (HHG) properties of H+3 model exposed to 800 nm-wavelength ultrashort laser pulse. The effect of electron interaction on the HHG spectra is less profound than at the cut-off frequency. We also calculated the HHG spectra for different internuclear separation values close to realistic one. Most of the calculated cutoff frequencies are beyond the three-step model’s prediction, and a preliminary scenario is suggested.