Earth-abundant molybdenum disulfide (MoS₂) has attracted considerable attention as a promising substrate for surface-enhanced Raman spectroscopy (SERS). Naturally occurring MoS₂ primarily exists in the semiconducting 2H phase, but its SERS performance is limited because active sites are typically confined to its edges. Furthermore, the irregular agglomeration of MoS₂ can lead to performance degradation, rendering the natural semiconducting material unsuitable for practical applications. Therefore, enhancing the performance of MoS₂ in the field of SERS is of crucial importance. Metal-organic frameworks (MOFs) are ideal materials for building efficient SERS substrates due to their tunable pore structures. Among various MOF materials, zeolitic imidazolate frameworks (ZIFs) have garnered significant interest owing to their well-defined polyhedral structures, homogeneity, and small particle sizes. Therefore, this study fabricated a MoS₂/zeolitic imidazolate framework-67 (ZIF-67) heterostructure by the hydrothermal method as a SERS substrate, which exhibits exceptional sensitivity with an enhancement factor of up to 6.68×10⁶ for rhodamine 6G. Moreover, the SERS performance remained almost unchanged after four months of exposure to air, demonstrating high stability and reusability. To evaluate the actual detection ability of this substrate, bilirubin was selected as the analyte, which is a clinically relevant metabolic waste. Since both high and low concentrations of free bilirubin can contribute to cardiovascular and cerebrovascular diseases, accurate monitoring of bilirubin levels is crucial for diagnosing bilirubin-induced disorders. Using the MoS₂/ZIF-67 substrate, label-free detection of bilirubin was achieved with a limit of detection (LOD) as low as 10^-10 M. The outstanding performance of this substrate can be attributed to the vertically aligned MoS₂ nanostructure, which exposes more active sites. Additionally, ZIF-67 provides a high specific surface area and abundant porous structures, offering numerous adsorption sites for target molecules. Furthermore, internal charge transfer facilitates the formation of a highly conductive 1T phase, thereby improving electrical conductivity. This work provides valuable insights into the rational design of noble-metal-free materials for highly sensitive SERS detection.