In railway construction, operation and maintenance, due to the influence of engineering geological conditions, natural and construction environment conditions and other factors, the safety of high cutting slope is one of the main key concerns of railway engineering. For the long-term stability of railway roadbed slope, this paper based on the slope safety factor and deformation relationship, long-term strength of rock and soil, and time relationship, established the safety factor of slope, shear deformation and time relation model, proposed three cut high slope stability evaluation index, including the long-term stability safety coefficient, the exponential value of deformation rate and the index of limit. Established four-level and eight-level early warning schemes for high slope safety and stability, specified the emergency treatment measures which should be taken under different early warning levels. At last, based on the actual engineering monitoring data, the stability of railway cutting high slope was evaluated and the corresponding warning level and warning scheme were put forward, It can provide reference for the long-term stability evaluation and early warning analysis of similar projects.