The invention discloses an automatic detection system and method of a high resolution printed circuit board. The detection system comprises a ray source, an object stage, a visible light collection camera, a ray detecting camera, a ray detecting image intensifier, a collection card, an image processing module and a control and analysis display module, wherein the object stage and the ray source are respectively connected with the control and analysis display module through a connecting line, the visible light collection camera and the ray detecting camera are respectively connected with the image processing module through the collection card, and the image processing module is connected with the control and analysis display module through a connecting circuit. The invention combines functions of visible light image navigation, X-ray detection, automatic analysis test marking and the like, is a detection for making quantification aiming to the quality of welding spots and tracing lines and realizes defect automatic detection of invisible welding spots and internal tracing lines.