Abstract: Pipeline Pump are increasingly doing useless work with the decrease of throughput year after year in Wei -Jing Oil Pipeline.Three pump units have been modified in succession in Xiangfan Oil Pump Station since 1989.The reasonable arrangement of the three pumps have been realized and cut down power consumption.After the modification, the operating optimization for the pump u-nits have been made in order to reasonably match with oil throughput, so as to increase the operating effeciency of pump units to a maximum.It is proved that the pump units modification brings about the energy saving in the Wei-Jing Pipeline.