Ground penetrating radar is an effective technology for detecting hydrates. Simulation test and study of the relationship between electromagnetic characteristics and gas hydrate saturation as well as other factors show that ground penetrating radar has great significance for permafrost hydrate exploration and reserve estimation in terrestrial area. Through production of samples by the laboratory the authors obtained a uniform natural quartz sand particle as a skeleton containing tetrahydrofuran hydrate and studied its dielectric constant. After the 1.5G high-frequency radar testing, it was found that the electromagnetic characteristics have obvious difference between the pure hydrate model and the THF hydrate model. When the saturation of the model of tetrahydrofuran hydrate is higher than 35%, the volume of hydrate increases, the dielectric constant of hydrate model increases too, and the radar speed decreases in the model. The THF hydrate does keep stability in nearly one hour at 10℃ room temperature and atmospheric pressure; when the hydrate and liquid tetrahydrofuran coexist in the pore of the model, the more the volume fraction of THF and the more liquid THF in the pore, the greater the dielectric constant of hydrate model is.