<p>Microbially induced carbonate precipitation (MICP) has shown promising applications in various geotechnical projects. However, there is limited research on the effects and mechanisms of cementing solutions on the strength and microstructural characteristics of biocemented granite residual soil. Therefore, biocementing tests of granite residual soil were conducted under varying cementing cycles, types, and concentrations of cementing solutions. Subsequently, the strength parameters and microstructure of cemented specimens were determined. The relationship between mechanical behavior and microstructural characteristics was systematically analyzed to elucidate the mechanisms by which microcrystal properties influence mechanical strength and disintegration resistance. The results show that specimens treated with 1.0&#xa0;mol/L calcium chloride exhibit the most significant strength enhancement. With an additional treatment cycle (from 8 to 14 cycles), the unconfined compressive strength (UCS) rises by an average of 419.84%, and the disintegration index can be reduced to less than 15%. Carbonate production rate and homogeneity are the main reasons for the differences in disintegration morphology between the various parts of cemented specimens, and crystal properties are the key factors for their enhanced disintegration resistance. The calcite generated by the low concentration cementing solutions has better structural morphologies, and the crystal structures are tightly packed in clusters. Vaterite is hydrophilic and soluble, easily transformed into aragonite or calcite in aqueous medium, so calcium acetate is unsuitable as a cementing solution for enhancing granite residual soils. In contrast, calcite crystals generated by 1.0&#xa0;mol/L calcium chloride are stable in nature, with well-developed crystal structures. The insights gained in this study contribute to a better understanding of strength properties and mechanisms of biocemented granite residual soils.</p>