Abstract: Located in the northeast of China, there is an overbridge crossing above an expressway. Its right abutment is seated on a rock masses slope with low carrying capacity. The slope and abutment basis had appeared obvious unstable evidence before completion. For the stability of abutment and slope, according to the in-situ situation, some effective reinforcement measures Were adopted, which include middle-high pressure grouting, pre-stressed anchoring, anti-sliding anchoring, etc. The software of FLAC was used to numerically simulate the reinforced structure, and the design parameters were attained. Engineering practice of the abutment-slope system verified effectiveness of the multi-reinforcement.