In order to cope with the multiple challenges of complex geological conditions, mutual interference between construction and operation, and ecological environmental protection during the widening-excavation of the existing slope in expressway reconstruction and expansion projects, in this paper, the slope widening-excavation works of a hub slope at the south of Shuikou Town of the Yangchun-Xinyi Expressway is studied to conduct a segmented risk assessment based on the fuzzy analytic hierarchy process (FAHP). The weights of each risk factor were determined by means of the Analytic Hierarchy Process (AHP), based on which, a multi-level risk assessment index system covering geological conditions, construction methods, construction environment and traffic organization is constructed and a sensitivity analysis of influencing factors during the slope widening-excavation process is conducted. The results indicate that the risk level of sections A-C in the widening-excavation works is classified as Level III, requiring the enhanced control measures, while the risk level of Sections D-H are classified as Level II, which can be controlled through conventional measures. The influence degree of weight values on the calculated value of risk degree is greater than that of index assignments, and weight value variations exhibit higher sensitivity in sections with higher risk levels. The findings of this study can provide a scientific basis for risk management in slope widening-excavation works on operational expressways and offer practical references for risk assessment and construction optimization in similar works.