The utility model discloses a synchronous double-material muck improvement system for an earth pressure balance shield, and aims to effectively improve the muck improvement speed and reduce the probability of cutter abrasion, mud cake formation and gushing to the maximum extent. The device comprises a foam stock solution storage tank and a liquid storage tank for storing a second muck improver. Wherein the foam stock solution storage tank is connected with the mixing box through a foam stock solution conveying pipeline, the mixing box is connected with a plurality of foam conveying pipelines,and each foam conveying pipeline is connected with a corresponding high-pressure gas conveying pipeline and then is connected into a corresponding foam generation pipeline. The liquid storage tank isconnected with a plurality of second muck improver conveying pipelines, each second muck improver conveying pipeline is connected with the tail end of the corresponding foam generation pipeline, and foam is mixed with a second muck improver, is connected to a nozzle in front of the cutterhead through a spraying pipeline and is directly and uniformly sprayed to a tunnel face in front of the cutterhead.