Abstract: A dynamic meso-scale model for non-straight steel fiber is proposed on the work of Chanvillard G. The model is time-dependent and related to the impact loading through the interfacial shearing stress along the embedded part of the steel fiber. Thus, properly setting the thresholds, a dynamic model of the fiber's debonding and pullout process considering the evolution of meso-damage is eventually constructed. The rate sensitivity of the reinforcing effect of the steel fibers can be demonstrated in this model. The model prediction fits the experimental data of Chanvillard G for non-straight steel fiber under static condition well.