Abstract: Under the CAP1400 containment overpressure release condition, the mixture of steam, non-condensable gas and radioactive materials in the containment will be discharged into the spent fuel pool so that the containment pressure could be reduced, and the radioactive materials could be removed by the spent fuel pool at the same time. In order to enhance the pool scrubbing effect of the spent fuel pool under such condition and to reduce the offsite dose consequence caused by the containment overpressure release, in this paper, several essential parameters specific to this pool scrubbing process are selected to conduct the sensitivity study to investigate their effect on the overall aerosol decontamination factor（DF）. Combing the sensitivity study results and engineering practice, several measures and suggestions used to enhance the spent fuel pool scrubbing effect are proposed, which could provide reference for the optimization design of the overpressure release device.