Abstract: To analyze the influence of reinforcement on the strength of expansive soil under dry-wet cycles, small-sized conventional ring knife specimens with vertical intermediate reinforcement were prepared by a two-step compacting method, and shear tests were conducted in the direction perpendicular to the reinforcement mesh. Direct shear tests considering the low-stress segment under five dry-wet cycles were carried out on unreinforced expansive soil and reinforced expansive soil, and the changes in cracks of expansive soil during the cycles were observed. The test results indicated that the cohesion of reinforced expansive soil was significantly improved and basically remained unchanged under dry-wet cycles, while the variation range of the internal friction angle after reinforcement was small. A strength prediction method for conventional large-sized geogrid-reinforced expansive soil under dry-wet cycles was proposed. The variation laws of surface crack ratio and volume crack ratio during dry-wet cycles, as well as the role of reinforcement in inhibiting crack development and strength degradation, were analyzed. It is recommended to use the volume crack ratio to predict the soil strength parameters. The research results can provide a reference for further revealing the mechanism of reinforcement in improving the stability of expansive soil slopes.