The invention relates to the technical field of bridges, in particular to a large-span bridge expansion joint cleaning device. The large-span bridge expansion joint cleaning device includes a cleaning wheel and a dust collection head which are arranged on a vehicle; and the cleaning wheel and the dust collection head are slidingly arranged on the vehicle by means of sliding modules. The dust collection head includes a housing; a spraying nozzle and a gathering lining are arranged in the housing; the gathering lining is arranged on an outlet end of the spraying nozzle, and a high pressure water spraying device is arrange on an inlet end of the spraying nozzle; a dust collection nozzle communicating with the inner part of the housing is arranged on the housing; and a brush assembly is detachably arranged on an opening end of the housing. The large-span bridge expansion joint cleaning device can use the cleaning wheel to loosen an expansion joint and use the dust collection nozzle to suck dust so as to achieve cleaning of the bridge expansion joint, is good in cleaning effect, is high in efficiency, and is low in energy consumption; and in addition, the dust collection head can perform high pressure spraying so as to clean dirt in the expansion joint.