An automatic online quality detection system of honeycomb core was developped based on the MATLAB software. The honeycomb paper core image obtained from the production line was processed and compared with standard template image using specific algorithm to collect the quality information of honeycomb paper core in practical production process. There are two keys in the comparing algorithm. One is to find the matched images, and the second is the similarity calculation between them. The system used a related template matching method to match the images and the pixelby-pixel comparison method for the similarity calculation, which can calculate the matching part quickly and efficiently.