In the precision manufacturing industry, the measurement of the thickness and tolerance of small parts is a crucial step. Common measurement methods mainly include contact and non-contact schemes. Contact measurement may cause damage to the measured parts due to contact with the surface, and the contact area can generate stress on the measured parts, potentially causing minor displacements that lead to inaccurate measurement results. Non-contact measurement offers the advantages of not needing to touch the measured parts, fast measurement speed, and flexible integration. Recent advancements in optical technologies have further enhanced the precision and reliability of non-contact methods, making them increasingly viable for industrial applications. Spectral confocal measurement systems are one type of non-contact measurement; therefore, designing a compact, high-precision, low-cost spectral confocal system is essential.By analyzing the components of spectral confocal systems, it was determined that the system to be designed mainly consists of two parts: the dispersive objective lens and the spectrometer, with defined design specifications. The complex and cumbersome entire spectral confocal system was divided into three subsystems using the concept of modular design. This approach not only simplifies manufacturing and assembly but also improves system maintainability and scalability.A hybrid diffractive/refractive spectral confocal system with a wavelength range of 400-800 nm based on APC (Angled Physical Contact) port type Y-fibers was designed, with a working distance of 10 mm and a working range of 2.1 mm. The design of each subsystem reaches or approaches the diffraction limit, and the lens shapes and tolerances are in line with manufacturing processes. The theoretical measurement resolution of the entire system is 350 nm.Designed a hybrid diffractive/refractive spectral confocal measurement system with a working distance of 10 mm and a working range of 2.1 mm. Compared to other confocal spectral measurement systems, this design utilizes the concept of modular design to modularize the complex and cumbersome entire ranging system. Furthermore, the hybrid diffractive refractive design effectively corrects chromatic aberrations while maintaining a compact structure, making it suitable for integration into automated production lines. The dispersive objective lens and the spectrometer share the same collimation module, which can be installed in conjunction with other modules, and the structure is unified. Future work will focus on experimental validation and further optimization for industrial deployment. In the optical system design, each system has good manufacturability and the relative cost of lens materials is low. Third-order and linear polynomials were used to fit the chromatic focal shift curves and position curves of the dispersive objective lens and the spectrometer, with minimum residual coefficients of 0.9996 and 0.9999.