Abstract: In order to keep the purity of SF6 gas, absorbent is used in SF6 electrical equipment. It controls moisture as well as adsorbs SF6 decomposition products. So the existence of absorbent influences SF6 decomposition components greatly. When considering the gas-insulated equipment diagnosing method using decomposition products as characteristic quantities, we must take the effect of absorbent into account. Therefore, experiments were conducted based on the partial discharge（PD） testing apparatus. In experiments partial discharge was generated using a needle-plane electrode in pure SF6 gas, and SF6 decomposition products were tested by gas chromatography mass spectrometer. The results show that SOF4, SO2 F2, SOF2 and SO2 are produced, whether absorbent exists or not. Each adsorption rate of components is not identical as adsorbent consumption increases.