Abstract: The local adhesion in the X-Ray images of SMT material plates has negative effects on the accuracy of counting and detection for components. A method based on the constraints of position information was proposed, which was used to improve the accuracy of segmentation and detection with the position information between components. Firstly, the center point and the starting components arranged in the inner ring were fit out on the basis of the components in a spiral arrangement rule. Then the dual constraints of normal position and priori position, which were based on the constraint model between the center point and different components, were finished to limit the region of target device. Finally, the segmentation for conglutination between components was completed by dividing the boundaries between components. Experimental results show that this method can improve the accuracy of the result of segmentation and detection. The detection error rate tested on different specifications material plates is controlled within 0.15% under the experimental conditions of 9 216 pixels effective image element and detail resolution of 110 1p/cm.