For revealing the behaviors of modified concrete materials against eroding from composite solution, accelerated deterioration tests of Portland concrete, polypropylene fiber concrete, fly ash concrete and concrete mixed with polypropylene fiber and fly ash were made under continuous immersion in two types of composite corrosion solutions, which were sulfate composite solution and magnesium composite solution. The compressive strength, splitting tensile strength and elastic modulus of modified concrete subjected to corrosion were detected. The results show that capacity of corrosion resistance of concrete is enhanced remarkably by modifying approach of mixing fly ash and polypropylene fiber into concrete. The deteriorated splitting tensile strength of modified concrete is able to be increased by 30%-60% compared with ordinary concrete. The research results are benefit to engineering design and application.