Transverse shrinkage cracking is considered to be one of the main factors leading to the degradation of sustainable service performance for asphalt pavement, but the effect of base layers on it is rarely studied. To investigate the effect of asphalt pavement base layers on transverse shrinkage cracking characteristics, this study analyzed and evaluated it through the test section data. The transverse shrinkage cracking test section data of four different asphalt pavement base layers were compared, and the variation characteristics of transverse shrinkage cracking under the influence of the base layer types and temperature were analyzed. Based on the conventional characteristics, the concept and calculation method of cracking area ratio (CAR) was proposed, and its rationality and accuracy were proved by calculation. It has been found that the CAR can reflect the longitudinal shrinkage performance of asphalt pavement. The shrinkage rate of a semi-rigid base is larger, while the shrinkage performance of a flexible base is better, and the shrinkage performance of the whole pavement is not affected by a small amount of cement. The research provides a practical basis for improving the anti-cracking performance of asphalt pavement and helps to enhance its sustainable service performance.