Abstract: To tackle high energy consumption and large vacuum fluctuations in steam-ejector vacuum system of WZ193A vacuum pre-conditioner, a three-stage, four-pump water ring pump replacement plan was designed and implemented, with comparative testing conducted at industrial site．Results showed that, after retrofitting, steam consumption during evacuation reduced from 239 kg/batch to 0 kg/batch, per ton tobacco leaves energy consumption dropped from 1 040 MJ/t to 478 MJ/t．Vacuum fluctuations were reduced to ±0.9 kPa, with no significant differences observed in tobacco leaf core temperature, moisture content, or re-moistening rate compared to pre-retrofit conditions．Results demonstrated that water ring pump energy-saving retrofit markedly reduced energy consumption and carbon emissions, providing a practical pathway for low-carbon upgrade of vacuum conditioning equipment．