The metric pump is widely used in the chemical industry and other industries which need fluid translation. It has the ability of accurate flow regulating. However, it is mainly by operating the hand wheel on the pump to regulate the flow of the pump at present. The accuracy of manual regulation is low, and the manual operated metric pump is not suitable to be used in the poisonous and dangerous circumstances. This paper chose AT89S52 as the main controller, which controlled the stepper motor. After reducing the speed by speed reducer, the stepper motor drove leadscrew to control the N-Shape Shaft, which is the flow regulating part on the pump. The system used LCD as the display unit, it can displayed the the setting values, and the values changed as the stepper motor moved. The system used 4×4 keyboard as the input interface, it has more keys which means more control funtions and inputing flow values is convenient. The experimental results indicate that the error between actual flow value and the setting value is within 2%. It reaches the factory demand. This flow regulation instrument has resloved unconvenience in manual regulation way and improved the control accuracy.