In order to solve the problems of low efficiency and poor accuracy in manual detection of water meter movement sensitivity, a set of water meter movement sensitivity detection system based on machine vision was developed. Designing an indirect detection algorithm based on the difference in the rotation angle of the pointer before and after ventilation. Using the least square method to find the center of the initial contour, dividing the pointer contour into four parts with the abscissa and ordinate of the center, calculating the standard deviation of the distance from the contour point of each part to the center of the circle and taking the smallest part of the standard deviation as the contour set to fit draw a precise circle, realizing the pointer center positioning, combining the Shi-Tomas corner detection algorithm and the distance feature from the needle point to the center of the circle to realize the needle point positioning; calculating the angle between the straight line and the horizontal line formed by the center of each sub-dial pointer and the needle point before and after ventilation, comparing the pulse number converted from the angle difference with the set pulse number threshold, and judging whether it is qualified. Experiments show that the system can efficiently complete the sensitivity detection of water meter movement while maintaining the accuracy of detection, and the accuracy of algorithm verification is as high as 99. 7%.