Conventional dispensing devices are typically semiautomation equipments, and the dispensing valve is driven by manually dispensing position and dispensing path, but the equipments are unable to adapt to some products which have certain dimensional tolerances, and the production efficiency can not reach the desired level. In order to compensate for the defects, the vision technology is applied to the measurement of dispensing position, and the automatic dispensing system which depends on the vision technology to obtain the dispensing position is designed. The program is edited by Visual C #, the images of the film are analyzed by eVision and the starting coordinate is obtained by Image preprocessing and morphological operation. Experimental results show that the dispensing accuracy of the system is up to 0.014 mm and the repeat accuracy is controlled within 0.012 mm, so the dispensing technology largely solves the problem of poor stability and low dispensing precision.