Abstract: To analyze the influence of reinforcement on the strength of expansive soil under dry-wet cycles, small-sized conventional cutting ring specimens, vertically reinforced at mid-height at are prepared by a two-stage compaction method, and direct shear tests are conducted in the direction perpendicular to the reinforcement mesh. Direct shear tests covering the low normal stress range under five dry-wet cycles are carried out on unreinforced expansive soil and reinforced expansive soil, and the changes in cracks of expansive soil during the cycles are observed. The test results indicate that the cohesion of reinforced expansive soil is significantly improved and basically remained unchanged under dry-wet cycles, while the variation range of the internal friction angle after reinforcement is small. A strength prediction method for conventional large-sized geogrid-reinforced expansive soil under dry-wet cycles is proposed. The variation patterns of surface crack ratio and volumetric crack ratio during dry-wet cycles, as well as the role of reinforcement in inhibiting crack development and strength degradation, are analyzed. The volumetric rack ratio is proposed as an effective indicator for predicting 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.