Addressing the issue that traditional endoscopes rely solely on morphological observations, which making it difficult to accurately diagnose early or subtle symptoms, a dual-modal endoscope integrating high-definition imaging and Raman spectroscopy detection has been designed. Its aim is to achieve high-definition full-field imaging with visible light and precise focusing of Raman detection light in a small field of view. Adopting a common optical path design, the sharing of the front objective group and the relay system not only reduces the diameter of the endoscope, but also lowers the cost. In the imaging system, it achieves an F-number of 7.3, visible light high-definition imaging with a full field of view of 70° and a small aperture, ensures a modulation transfer function of no less than 0.12@175lp/mm at a working distance of 10mm, and maximum distortion controlled within 11.64%, these features effectively minimize aberrations and improving imaging quality. At the Raman detection end, a 785nm excitation wavelength is selected, with a spectral range covering 785~1100nm, and precise focusing is achieved. Compared to conventional endoscopes, it not only retains the morphological observation function but also acquires real-time information on molecular structure and material composition through Raman spectroscopy technology, thereby enhancing diagnostic accuracy.