*

In two-dimensional materials, Moiré superlattices formed by stacking two monolayers with lattice constant mismatch or rotational misalignment have been widely used to manipulate their electronic and optical properties. Here, we employ low-frequency Raman measurements and DFT calculations to demonstrate atomic reconstruction in the MoS₂ homobilayer with a small twist angle (θ). For 0°＜θ≤3.5°, only interlayer Raman mode of 3R stacking with stable peak position is presented, indicating the overwhelming expansion of stable stacking in small twist angle due to structural relaxation. For 3.5°＜θ≤6°, the small Moiré supercell with weak relaxation results in mixed in-plane and out-of-plane vibrations. The shear mode quickly disappears with an increasing twist angle, while mixed breathing modes are observed. Our work provides a novel strategy to understand and monitor the evolution of structural relaxation in moiré superlattices in two-dimensional van der Waals materials.