Abstract: This paper presents a method that the working characteristic curve of screw pump could be quantitatively acquired by simulating method.The working characteristic curve could be used to evaluate the performance of screw pump under different configuration,operating mode and operating parameter.This method can be applied in providing support to well and pump selection,operating mode analysis and breakdown diagnosis.It can also be applied in establishing detecting criterion of screw pump,appraising product quality and diagnosing supply-ejection relationship.