Abstract: The quality of the mesoscopic skeleton structure of asphalt mixtures has a significant influence on their macroscopic pavement performance, especially rutting resistance. However, it is often overlooked in traditional design, construction, and quality inspection systems. Skeleton contact parameters are effective indicators for characterizing the mesoscopic skeleton interlocking state and quality. This paper proposes a detection method for skeleton contact parameters based on digital images of asphalt mixture structures. Digital image processing techniques are employed to extract coarse aggregate contours. Average coordination number, free coarse aggregate content, and skeleton ratio are defined to quantitatively evaluate skeleton contact characteristics. Utilizing a highway project in Guangdong Province as an application case, the method was applied to verify laboratory mix design and inspect on-site construction quality. The research results demonstrate that: 1) This method can effectively quantify the mesoscopic skeleton structure quality of asphalt mixtures, exhibiting good practicality and operability; 2) Skeleton contact parameters show a significant quantitative correlation with rut depth, serving as effective quantitative indicators for evaluating the rutting resistance of asphalt mixtures; 3) Skeleton contact parameters can be used to validate the rationality of the production mix design and assess the quality of on-site paving and compaction. This research provides an important supplementary mesoscopic evaluation tool for optimizing asphalt mixture mix design and controlling construction quality.