The invention discloses an extensible rapidly-assembled trussed deck type arch bridge. The extensible rapidly-assembled trussed deck type arch bridge comprises upper chord members, lower chord members, webs, transverse braces, upright post bases, upright posts, rubber supports and bridge panels, wherein the upper and lower chord members are arranged in parallel; the middles of both sides of the upper and lower chord members are provided with stripy flange belts respectively, and the webs are positioned between the upper and lower chord members; adjacent upper chord members and adjacent lower chord members are connected through the transverse braces; the two ends of the transverse braces are connected to the flange belts through bolts; the bridge panels are erected on the upper chord members through the upright posts, and the upper ends of the upright posts are supported below the bridge panels through support grooves; the rubber supports are arranged in the support grooves; the lower ends of the upright posts are arranged on the upper chord members through the upright post bases. Moreover, the arch bridge is light, contributes to bringing the mechanical properties of materials into play, is quick for splicing, easy to maintain, short in construction period and very suitable for building small and medium-sized bridges in cities, and has remarkable social benefit and economic benefit.