Abstract: The pumping wells in Tahe Ordovician reservoir flush frequently, since oil emulsion causes polish rod lag and high current. Flushing causes long period of discharging flushing liquid and it always operates shortly. General oil-well pump and centrifugal pump cannot fit oil emulsion. This paper analyzes the failure of screw pump and researches other papers. The surface drive screw pump is improved in sucker rod and rubber. It is applied in well TK241CH and fits oil emulsion.