This　paper　discusses　questions　on　structural　health　evaluation　of　bridge　on　service.　A　model　of　health　evaluation　of　bridge　is　set　up.　Influence　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,　the　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　shows　that　this　method　is　well　fit　to　evaluate　the　structural　health　of　bridge　on　service.