The invention discloses a flexible material used for modifying concrete as well as a preparation process and application of the flexible material. The flexible material comprises the following components by mass percent: 30%-40% of rubber powder, 30%-40% of rubber particles, 0.5%-1.5% of polypropylene fibers, 3%-8% of coal ash and 20%-28% of mineral admixture, wherein the mineral admixture is mineral powder or mineral slag powder, and zinc stearate on the surfaces of the rubber particles and the rubber powder is removed through strong base solution. The preparation process of the flexible material comprises the following steps of: firstly preparing the rubber powder and the rubber particles, and secondly uniformly mixing. The application of the flexible material is as follows: a part of fine aggregate of common concrete is replaced by the flexible material to prepare semi-rigid concrete by adopting an equal mass replacement method. The preparation process is simple in steps, simple and convenient to operate, low in input cost and good in use effect. The semi-rigid concrete prepared by the flexible material can make up defects of small deformation, large fragility, low tensile strength, and the like of the existing common concrete.