In order to realize the intelligentization of circuit board fault detection, an electroluminescent circuit board fault detection system was designed, its structure was introduced, and a circuit board fault detection method was proposed.In the image preprocessing module, the original image is enhanced by gray scale, and the predetermined bits of the original image are realized by using the method. The code of PCB file saved in the form of ASCII code is deeply analyzed, and the PCB file data is read by MATLAB software, saved in a specific structure, and the template image is drawn by drawing function. Using color image segmentation method to extract the interested part of the circuit board pre-position image, and then the template image drawn by software is registered with the original image of pre-position, and a more ideal result is achieved. Experiments on luminescent circuit board fault detection and location show the effectiveness of the method.The experimental results show that the method has less damage to the circuit board, and is effective in detection, fast operation, short cycle and easy to implement in engineering.