In order to study the evaluation method of bridge health state, a continuous rigid frame bridge was taken as the engineering background, and a multi-source data fusion system of continuous rigid frame bridge was constructed by comparing and analyzing three data fusion methods. Based on the research of data-level fusion method, the health monitoring system of continuous rigid frame bridge was established. Based on the analytic hierarchy process (AHP) and the big data of bridge supervision and inspection, the health status of the bridge was evaluated according to the order of sub-components, components and the whole structure of the bridge. By comparing the evaluation result with the current standard, it is found that the evaluation result of this method is closer to the engineering practice.