Abstract: As the technology developing in the modern time, the requirements of detecting is not only finding out whether there are any flaws, but also getting some reliable analysis by the visualized image of the flaw. For these defects, it usually uses the universal ultrasonic testing method to detect them, but for the especial, small or thin metal composites, it has a lot of difficulties in the universal testing method, even sometimes, it can not be detected. The study is using the F-scan ultrasonic imaging testing system to detect the bonding layer of the metal composites. The establishment of whole wave train recording and processing of ultrasonic testing signal makes the system a full-information processing ability of the waveform features and flaw features. Then through analyzing and evaluating the information of the images, the layered detects of bonding layer can be found out. This paper is to present the quantitative direct results for the connective quality of bonding layer, which can avoid missing the defects or mistaking the defects. Present method can realize the detection and evaluation of the metal composite materials by diffusion-welding.