To investigate the feasibility of comprehensive utilization of coal gangue in road engineering, this study selected coal gangue from the Ningxia region to conduct liquid-plastic limit tests, compaction tests, and triaxial tests. The characteristics of coarse and fine coal gangue aggregates were compared and analyzed. Furthermore, engineering practice was carried out based on the Shang gouwan Logistics Park project. The results show that the liquid limit of the coal gangue is 31.26% and the plastic limit is 21.17%. The maximum dry density obtained from the compaction test is 2.19 g/cm³ , with an optimal moisture content of 4.5%. The stress-strain curve of the fine coal gangue aggregate exhibits strain-hardening behavior, whereas that of the coarse aggregate exhibits strain-softening behavior. Based on the experimental findings, coal gangue was utilized as a partial replacement for crushed stone in the subgrade construction. Field monitoring data indicate that the maximum settlement of each cross-section is less than 9.0 mm, and the differential settlement between adjacent sections is less than 3.0 mm. These values meet the stringent requirements for uneven settlement of pavement structural layers and comply with industry standards, thereby providing a reliable quality assurance for subsequent pavement construction.