To study the dynamic performance of C-type cold-formed thin-walled steel members under transverse impact loading, two groups of 12 members were selected for impact test. The deformation modes and displacement extremum of the test members were compared with the results of ANSYS/LS–DYNA finite element simulation and the results showed that the deformation modes of the two members were similar, and the difference of displacement extremum was less than 8.0%, which indicated that ANSYS/LS–DYNA finite element model could accurately and effectively simulate the dynamic response of the steel member. Then, the numerical model was used to analyze the influence of different impact parameters (density, velocity and angle) on the deformation mode and dynamic performance of C-type cold-formed thin-walled steel members successively. The results showed that the maximum impact force of members increased by 25.5%, the maximum vertical displacement was 20.30 mm, and the proportion of stable strain energy in the peak value was basically maintained at 60.0%, when the density of impactor increased by 2000 kg/m3 in the range of 2000～8000 kg/m3 when the velocity of the impactor increased by 3 m/s in the range of 3～9 m/s, the maximum impact force of the member increased by 79.1%, the maximum vertical displacement was 26.78 mm, and the proportion of the stable strain energy in the peak value basically remained at 60.0% when the impact angle of the impactor increased from 30° to 90°, the maximum amplification of impact force was 41.4%, the maximum vertical displacement was 20.09 mm, and the proportion of stable strain energy in the peak value was between 60.0% and 70.0%. Eventually, the deformation and degree of damage of the member were affected by the change of impactor density, velocity and impact angle, and the impact velocity had the most outstanding influence on the deformation of the member.