Abstract: China is the country with the most serious landslide disasters in the world, and the number of landslide disasters and disaster losses have been in the first place of all kinds of geological disasters for a long time. Reservoir-bank slopes are affected by reservoir-water-level fluctuations, groundwater, rainfall, loading, excavation, and other coupled factors, making their deformation and instability mechanisms particularly complex. Real-time monitoring and predictive assessment of slope deformation and instability under different loading and environmental conditions are therefore essential for hydropower-project safety and reservoir-bank stability. Taking deformation and instability monitoring of reservoir-bank slopes as the research background, this study summarizes the typical triggering factors of reservoir-bank slope deformation and instability, and compares the principles and applicability of FBG, OTDR, BOTDR, BOTDA, BOFDA, DAS, and other fiber-optic sensing technologies used in slope safety monitoring. The fiber-optic monitoring workflow for reservoir-bank slopes is described from the perspectives of sensing-cable selection and instrument configuration, and typical fiber-optic sensing technologies and mainstream commercial equipment are compared. On this basis, an integrated DFOS-based slope safety monitoring system is proposed. System design and functional implementation are discussed in terms of data acquisition, reliable transmission, intelligent processing, targeted early warning, and scientific decision-making. The accuracy and reliability of the integrated system are verified using fiber-optic monitoring results from the Majiagou slope in the Three Gorges Reservoir Area. The results provide new technical approaches for safety monitoring and stability assessment of reservoir-bank slopes.