[Purposes] The current "Highway Performance Assessment Standards" primarily relies on surface distress for condition evaluation, lacking a quantitative method for assessing internal structural cracks in asphalt pavements. This study aims to establish an evaluation model that comprehensively reflects the morphological characteristics of internal structural cracks and their impact on road bearing capacity. [Methods] A combined subjective-objective method was adopted to construct a morphological characteristic evaluation model based on crack geometric dimensions and a bearing capacity evaluation model based on deflection basin data. Firstly, a three-dimensional pavement model containing structural cracks with different geometric features (width, length, reflection depth) was established using the finite element software Abaqus to simulate the falling weight deflectometer (FWD) test, obtaining the surface deflection basin and calculating the modified Structural Strength Coefficient (SSR""). Subsequently, the correlation between SSR"" and each crack geometric characteristic was analyzed, and regression models were established. [Findings] Numerical simulation results indicate that crack width shows no significant correlation with SSR"", while crack length and SSR"" approximately follow a power function relationship, and the crack reflection depth and SSR"" approximately conform to an S-shaped function relationship. Based on these functional relationships, the weights of each indicator were determined by quantifying the overlapping characterization of geometric features by both the morphological and bearing capacity models. Ultimately, a comprehensive evaluation model for internal cracks, integrating morphological characteristics and structural bearing capacity, was formed. [Conclusions] The comprehensive evaluation model developed in this study enables the quantitative assessment of internal structural cracks in semi-rigid base asphalt pavements. It addresses the deficiency in the current standard in this aspect, providing a theoretical basis and methodological support for structural performance-based preventive maintenance decision-making.