In view of the current situation and existing problems of containerized steel coil loading at home and abroad, the work aims to design a 20 ft special platform container (internal dimensions:5.9 m×2.35 m×2.393 m, door width:2.342 m, door height:2.28 m) for coil steel and analyze its mechanical properties. A 3D model of the platform container was built by SolidWorks to analyze with the load and constraint under the shunting impact condition. A finite element model was established by Ansys Workbench and the finite element computation on the platform strength was conducted. The equivalent stress and displacement of the platform container under the most unfavorable conditions was obtained. Stress concentration occurred to the supporting surface of the coil steel bracket and the inner side wall of the corner fitting. The maximum working stress value was 234.01 MPa, which did not exceed the allowable stress of structural steel material (246 MPa). The maximum deformation of the weakest link was 1.0572 mm, within the allowable range. The simulation results show that the platform container meets the structural strength requirement.