Microplastic pollution poses a significant environmental challenge, with particles ranging from micrometers to millimeters contaminating ecosystems worldwide. Traditional Raman microspectroscopy struggles to balance spatial resolution, field of view, and throughput, especially at low particle concentrations. Here, we present a high-throughput Raman spectroscopy (HTS-RS) platform that overcomes these limitations by combining a 3.15 × 2.10 mm2 field of view with a spatial resolution of 1.4 μm, enabling rapid, label-free detection and classification of microplastics across a wide size range. The system integrates automated particle recognition, autofocus correction, and Raman spectral acquisition into a seamless workflow, reducing user intervention and accelerating data acquisition. Validation on reference microplastic mixtures demonstrated precise detection from 7 μm to over 400 μm, with robust morphological and chemical characterization. With its high sensitivity, throughput, and automation, our platform sets a new benchmark for microplastic monitoring and provides a scalable solution for environmental screening applications.