According to the principle of least square method, the H-Q curve of the centrifugal pump is fitted with power function, polynomial and exponential function, and the error analysis of fitting curve is carried out by using the data of factory performance curve. The results show that the accuracy of fitting with polynomial is higher. After the fitting is completed, the centrifugal pump will have a certain deviation from the factory performance curve provided by the equipment manufacturer in actual operation. Because the number of pump operation data may be very small, the output performance curve is corrected by moving up and down from left to right. To correct the factory performance curve, the actual engineering data are used to correct the performance curve, which makes the corrected performance curve more applicable to actual production. An example analysis shows that the head is calculated to be 60 m without correction and 94 m after calibration. Assuming that a pump can provide a head of 60 m, if we use the pump scheme without correction, one pump is turned on, but in fact one pump is far from satisfactory. Therefore, the calibration of the pump's factory performance curve has a great influence on the subsequent pumping schemes.