Sewage pumping station is pumping station import at the sewage treatment plant. Its role is to collect the wastewater from the sewage pipe network to subsequent wastewater treatment process facilities. The water level is usually low in sewage collection pipe network. And many wastewater treatment facilities is based on elevation settings. So it is necessary to use lift pump to improve lift of the collected sewage, using high gravity sewage errands subsequent process in order to reduce energy consumption. The traditional way of pumping generally has the shortcomings: the waste of power resources, low efficiency, poor reliability, low degree of automation, which seriously affects the urban sewage treatment capacity. This paper, views pump station control system at the sewage treatment plant as the background, researches frequency control constant pressure control system based on PLC, realizes the energy efficient, automated and reliable direction of development of the sewage pumping station.