Abstract: An optimization control scheme based on particle swarm optimization with division of work is proposed for pre-denitrification wastewater treatment process.Taking the benchmark simulation model(BSMl) as basis,and considering the effluent quality,the aeration and pumping energy consumption,and the best setting value of lower level PI(proportional-integral) controllers are optimized dynamically so as to improve the water quality of effluent with minimal energy consumption. The particle swarm optimization with division of work strategy has stronger global searching ability,and the simulation results show that using the presented optimal control scheme,the operation cost is significantly reduced while the effluent quality can meet the integrated wastewater discharge standard.