Based on the improved AHP method and entropy method, a nonlinear objective programming method for determining index weights is proposed, which combines subjective and objective weight information, which can not only make full use of objective information, but also meet the subjective wishes of decision makers. At the same time, in view of the existence of many gray information in the optimization of bridge reinforcement scheme, gray correlation analysis is used to optimize the scheme. Finally, the rationality and practicality of the decision-making method are illustrated by engineering examples, which provides a new idea for the scientific decision-making of bridge reinforcement scheme.