The efficient recovery of shallow lunar regolith with minimal structural disturbance is critical for accurate geological analysis. This study employs the Discrete Element Method (DEM) to evaluate the coring performance of two drill bit types-Polycrystalline Diamond Compact (PDC) and Cutter Blade-under simulated lunar conditions. Multi-scale particle models were constructed in EDEM software and calibrated through repose angle experiments. A comprehensive assessment framework was established based on stratigraphic integrity, drilling loads, porosity, and force chain characteristics. Results indicate that regolith particles enter the coring tube via progressive stress bubble formation and collapse. The Cutter Blade bit exhibited lower drilling pressure, smoother torque response, and reduced sample disturbance compared to the PDC bit, indicating its suitability for low-disturbance shallow lunar coring operations.