从理论上论证了排水装置效率随水泵流量增加而增加的变化规律,提出并论证了一种确定水泵不发生汽蚀时最大工况流量的方法,还提出并论证了一种确定泵配套电机不过载时最大工况流量的方法;进而提出了水泵最佳工况点的概念,即在确保水泵不汽蚀和电机不过载的条件下使排水装置效率最高时泵的工况点,并给出了其确定的步骤和方法. It is demonstrated theoretically that the efficiency of the drainage device increases with the increase of the pump flow rate. A method to determine the maximum operating flow without cavitation of the pump is proposed and demonstrated. A method to determine the pump supporting motor is also presented and demonstrated Then the concept of the best working point of the pump is put forward, that is, the working condition point of the pump is given when the efficiency of the drainage device is maximized under the condition of ensuring that the pump does not cavitate and the motor does not overload. The steps and methods of its determination.