The features of fixed time control, fixed volume control and backfeed control of the automatic control system of MGB pulp pump are briefly described. Analytic comparision and on-site application show that the automatic control system realized by backfeed control method has the best result. It can not only solve the problem of accumulated error due to unmatched flowrate, but also reduce the operation cost and raise the safety and reliability of the pump operation. The application of programmable controller i...