A decomposition-dynamic programming aggregation method, which was applied to solve the mathematical model of daily optimal operation with adjustable-blade for multiple pump units in single pumping station, has been proposed. Taking minimal daily electric cost as objective function, the water quantity pumped by units as coordinated variable, this model was decomposed into several sub-models of daily optimal operation with adjustable-blade for single pump unit, in which the blade angle was taken as decision variable, the discrete values of water quantity pumped by each unit as state variable, and was solved by means of dynamic programming method. The constructed aggregation model takes water quantity pumped by each pump unit as decision variable, the discrete values of water quantity pumped by pumping station as state variable, and was also solved by dynamic programming method. This method could solve the optimal operation issues for multiple pump units with different types or performance differences in single pumping station. Taking operation of No.4 Huaian Pumping Station as a study case, a set of optimization results was obtained.