Corrosion of steel bars will lead to cracking of rubberized concrete and reduce the durability of rub-berized concrete. The variation of rust expansion reaction caused by corrosion of steel bars can roughly reflectthe cracking process of rubberized concrete. Therefore, in this paper, the reaction force caused by uniform corro-sion and expansion of a single steel bar in rubberized concrete is studied through meso numerical simulation.The results show that : With the increase of corrosion degree of reinforcement, the steel rust expansion reactionfirst increases and then decreases, and the time of the inflection point of rust expansion reaction corresponds tothe time of concrete cracking; With the increase of corrosion degree of reinforcement, the mortar in the upperhalf of the reinforcement is always damaged first; and the smaller the thickness of concrete protective layer, theeasier the rubber aggregate concrete cracks; The thickness of the protective layer remains unchanged, and thelarger the diameter of the reinforcement, the easier the rubberized concrete cracks; In the calculation model, thesize relation of the average rust expansion reaction of reinforcement corresponds to the rubber aggregate contentof 10%>5%>8%. The research results of this paper have guiding significance for the study of corrosion reactionof rubberized concrete.