Abstract: In order to meet the requirements for the flexibility of concrete support materials in deep and large deformation conditions, composite fiber EGC materials were produced by using domestic raw materials. Through the experiment of the specimen, the composite fiber EGC material constitutive was obtained. The convergence characteristics of U-shaped steel and EGC materials were numerically calculated by using COMSOL. Analysis of the simulation results shows that when ordinary concrete support is used, the concrete at the bottom of the straight wall and the vault is prone to damage. U-shaped steel and ordinary concrete supports have not improved the phenomenon, and the EGC material produced can adapt to the operating conditions. Through the study in this paper, the constitutive structure of EGC materials with CaSO4 whiskers was obtained, and the adaptability of EGC materials to large deformation conditions was discussed.