Abstract: The problem of LCO absorbent entrainment of dry gas reabsorber in FCCU is analyzed. It is thought that relative serious foam system formed in the reabsorber is the reason for the entrainment when the high density FCC LCO is used as an absorbent. After the replacement of FCC LCO absorbent with top cycle oil, the liquid entrainment of dry gas is eliminated and the absorption efficiency is improved greatly. It is suggested to use top cycle oil as absorbent for FCC dry gas reabsorber to eliminate entrainment and improve absorption efficiency.