Abstract: This paper discusses questions on structural health evaluation of bridge on service. A model of health evaluation of bridge is set up. Influene effects of bridge health were analyzed. Based on service conditions of the bridge and results of expert investigation, weights and evaluation matrixes are put forward. Furthermore, method of multi-phase fuzzy comprehensive evaluation is given for appraising damaged bridge structure, which establishes the foundation of health evaluation of bridge on service. An example shown that this method is well fit to characteristics of questions on structural health evaluation of bridge structure.