Abstract: The magnetic pressure distribution and deformation characteristics during the dynamic expansion and deformation of aluminum alloy cylindrical shells with different axial heights driven by electromagnetic coils was analyzed by the ANSYS multiphysics coupling field finite element simulation, and compared with the experimental results. The results show that the finite element model could accurately simulate the radial magnetic pressure distribution and deformation of the cylindrical shell driven by the electromagnetic coil. When the height of cylindrical shell was 20 mm, the radial magnetic pressure at the end was greater than that in the middle, and occured concave uneven expansion. When the height of the cylindrical shell was 30, 40 mm, the radial magnetic pressure at the end was smaller than that in the middle, and occured convex uneven expansion. When the height ratio of the cylindrical shell and the coil was about 0.7, the radial magnetic pressure was basically the same at the end and middle, and distribution of radial magnetic pressure was uniform.