Abstract: Explosion experiments of three concrete-filled steel tube piers and one composite concrete-filled steel tube piers under different charge were deployed, with a TNT charge being 3 kg and 50 kg, respectively. The cylinder overpressure distribution, residual deformation and failure pattern were obtained. With the finite element analysis, the dynamic response, failure mode and parameter influence of concrete-filled steel tube piers under blast load were studied. The results show that compared with the composite concrete-filled steel tube piers of 50 mm core steel tube diameter and 4 mm thickness, the ordinary ones are better at resisting deformation while the outer diameter is 273 mm, the TNT charge is 50 kg and the scale distance is 0.14 m/kg^1/3. Based on the experimental results, multi-material flow-solid coupling simulation method was established, which effectively simulated the dynamic response of the concrete filled steel tube piers under explosion loads. Typical destruction paradigm can be categorized into flexural damage under low peak overpressure-long duration blast loading, shear fracture under high peak overpressure-short duration blast loading and bending-shear failure between the above two cases. Residual deformation is negligible when the scale distance is more than 0.3 m/kg^1/3 and the explosive charge is 50 kg. Enhancing the core concrete's strength grade and enlarging the steel ratio can effectively bring down the residual deformation. Increasing the yield strength can reduce the residual deformation, however with little significance when the yield strength is greater than or equal to 345 MPa.