Current testing methods used in highway projects typically meet the necessary requirements for construction, but they tend to focus on assessing the production and construction parameters of asphalt rather than providing an accurate representation of its microstructural characteristics. As a result, these traditional methods may not fully capture the intrinsic properties of asphalt that significantly influence its long-term performance. Consequently, as technology advances, an increasing number of researchers are focusing on studying the mechanisms of asphalt at the microscopic level, aiming to better understand its pavement performance. This study utilizes Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Gel Permeation Chromatography (GPC) to conduct both qualitative and quantitative analyses of the chemical functional groups and thermal properties of various asphalts. By examining the changes in the microscopic properties of asphalt before and after aging, the research seeks to understand how these molecular-level characteristics impact the macroscopic performance of asphalt in road applications. Specifically, the study focuses on identifying how alterations in chemical composition and molecular weight distribution influence factors such as durability, flexibility, and resistance to environmental stressors. The insights gained from this analysis aim to establish a scientific foundation for further investigations into the factors affecting asphalt’s road performance, ultimately guiding the development of more durable and resilient asphalt formulations.