<p>Pile foundations are a common type of foundation structure in engineering, suitable for complex geological conditions such as weak foundations, liquefiable soil layers, uneven foundations, and deep overburden layers, providing stable bearing capacity. Side grouting for piles involves injecting grout into the soil surrounding the pile, filling the voids in the soil, consolidating the soil, and enhancing the frictional resistance between the soil and the pile surface, thereby increasing the bearing capacity of the pile foundation. Microbial grouting is a new technology that uses microbial metabolic activities to improve the physical and mechanical properties of soil. Bacterial liquid thickening technology can improve the adsorption capacity of bacteria on the surface of the soil to be treated and between particles. In order to explore the reinforcement effect of microbial grouting on the sand around the pile, this paper compares the settlement and bearing capacity of the pile through the vertical loading test of non-grouting Group and grouting Group. The influence of calcium carbonate distribution around pile on pile side friction and pile end earth pressure is studied. The results show that microbial grouting improves the bearing performance of pile foundation, the effect of grouting on pile foundation reinforcement is remarkable, the ultimate bearing capacity of pile is effectively improved, the settlement of pile under the same load is also significantly reduced, and the efficiency of deep grouting is higher than that of shallow grouting. Microbial grouting improves the pile side friction and pile end earth pressure, which gives full play to the side friction compared with the non-grouting Group. Bacterial liquid thickening technology can realize directional reinforcement and improve the reinforcement effect of microbial grouting.</p>