In the field testing of electrical oils using terahertz technology, it is often difficult to avoid the influence of temperature on the results. To explore the impact of temperature on the detection results, a self-made temperature control device was used in the range of - 30 ~ 40℃ to perform terahertz detection on transformer oil, 0.01 mol/L methanol, formic acid, and furfural solutions. The results show that as the temperature increases, the peak value of the sample's time domain spectrum gradually decreases, and the time delay of the peak also gradually decreases. The absorption coefficient of the corresponding samples gradually increases, while the refractive index gradually decreases. The average was taken for the absorption coefficient spectrum and refractive index spectrum at 1.2 THz and within the range of 0.2 ~ 1.6 THz, respectively. Polynomial curve fitting was performed on the average data. An artificial aging sample with an oil-paper ratio of 20∶1 was used to verify the fitting curve. The fitting curve can compensate for the terahertz detection results at different temperatures, providing a reference for the field application of terahertz.