Microbially induced carbonate precipitation (MICP) is an innovative ground improvement technique that strengthens soil by facilitating the precipitation of calcium carbonate at particle contacts. The Discrete Element Method (DEM) provides a powerful tool to model the microstructure of biocemented sand at the particle-contact scale, enabling the prediction and explanation of its macroscopic mechanical properties, thus complementing experimental studies. In this study, biocemented sand is simplified as a combination of clean sand and cementation. First, with an RVE-scale particle packing, the parameters of Fontainebleau sand are calibrated and kept constant to isolate the influence of cement content and distribution on macroscopic mechanical properties. Based on the simplified morphology and distribution of cementation, the bond volume and spatial distribution for a given calcite content are determined. These cementation contact characteristics in DEM simulations are compared with CT scan data of biocemented Fontainebleau sand. Drained triaxial shear tests are conducted with the calibrated model to quantitatively assess the effects of cementation distribution, strength, and modeling approach on macroscopic mechanical properties. The modeling methodology is then applied to simulate biocemented Ottawa sand to evaluate its general applicability. Additionally, the shear wave velocity of the DEM sample is measured and compared with experimental results. By linking the microscopic cementation state to macroscopic shear wave velocity, this study aims to provide deeper insights into the mechanical behavior of biocemented sand from a microscale view.