Cryo-electron microscopy is a pivotal technique for resolving biological ultrastructure, where high-quality sample preparation, particularly cryo-thinning for thick samples, is essential. Traditional cryo-thinning techniques, such as cryo-ultramicrotomy, face challenges including sample compression artifacts, operational complexity, low efficiency, and insufficient positioning accuracy, which constrain in situ structural biology research. Driven by the increasing demand for high-fidelity, high-precision in situ observation, correlative light and electron microscopy has become the core development direction. The Chinese Academy of Sciences Scientific Instruments High-End Instrument Research Institute（Beijing） and the Institute of Biophysics，Chinese Academy of Sciences team have successfully commercialized an innovative achievement—the ELI-Triscope System. This system realizes groundbreaking “three beam co-focusing,” integrating an inverted fluorescence imaging system. By monitoring the actual fluorescence signals of target molecules, it achieves “cutting while seeing,” resolving the traditional “blind cutting” dilemma. With positioning accuracy better than 200 nanometers, it enhances the capability for targeted thinning of subcellular structures. Simultaneously, by eliminating ice contamination risks associated with sample transfer, it drastically reduces sample preparation time to approximately 45 minutes per sample. This provides robust support from a domestically developed tool for the precise analysis of organelle-scale in situ three-dimensional structures.