Abstract: Coating semiconductor substrates with metal–organic frameworks (MOFs) can significantly enhance their electromagnetic field amplification capability, thereby overcoming limitations in surface-enhanced Raman spectroscopy (SERS) applications. However, the electromagnetic enhancement performance of semiconductor substrates is highly sensitive to microstructural parameters, resulting in poor SERS signal uniformity and making it difficult to meet the requirements of precise quantitative detection. In this study, ZnO nanoparticles with an average diameter of approximately 350 nm were used as precursors to synthesize ZnO@ZIF-8 core–shell nanoparticles. These nanoparticles were further employed as assembly units to fabricate large-area, orderly arranged nanoparticle films, effectively suppressing SERS signal fluctuations caused by microstructural variations and random aggregation of ZnO@ZIF-8 nanoparticles. Furthermore, the characteristic peak of ZIF-8 was used as an internal standard to correct signal variations induced by testing conditions and environmental factors, thereby further improving the uniformity of ZnO@ZIF-8 films for volatile organic compound (VOCs) detection. Accurate quantitative detection of various aromatic VOCs molecules, including aniline, nitrobenzene, and styrene, was achieved, with a limit of detection as low as 10⁻⁶.