SF5CF3 was identified recently as a potent greenhouse gas with strong radiative force and long atmosphere residential life. Spark discharge method was used to take simulative investigation on the elimination of SF5CF3 from atmosphere under discharge here. The results show that SF5CF3 was dissociated under discharge and formed some compounds containing S, F, O and C. The dissociation of SF5CF3 was reduced if the system existed H2O, but it was independent of the amount of H2O. The rate coefficients were estimated to be 0.011s(-1) under moisture circumstance when the system total pressure was about 31 kPa. And the increase of the system pressure would cause exponential decrease of SF5CF3 dissociation. The reactive mechanism was argued based on the experiment results and the sinks of SF5CF3 under lightning (one of the discharge in the atmosphere) was estimated to be 53.6 kg x a(-1).