Purpose <p>In this paper, a magnetorheological (MR) semi-active seat is developed to improve ride comfort and observation-aiming effectiveness of armored vehicle occupants.</p> Methods <p>First, the structure, elastic element, and damping element of the MR semi-active seat are designed, and a hyperbolic tangent mechanical model for the magnetorheological damper is established based on mechanical performance test data. Then, the bench vibration tests are conducted on the MR semi-active and the traditional vibration attenuation seat to compare and analyze their transmission characteristics. Finally, a variable universe (VU) fuzzy controller for MR semi-active seat suspension is designed, and its vibration attenuation performance under random road excitation is evaluated.</p> Results <p>The results show that the performance of the developed MR semi-active seat is much better than that of the traditional vibration attenuation seat. The MR semi-active seat suspension based on VU fuzzy control has strong self-adaptability, and the control effect is better than that of traditional fuzzy control and sky-hook on-off control.</p> Conclusions <p>The MR semi-active seat suspension based on VU fuzzy control can better balance armored vehicle occupants’ ride comfort and observation-aiming effectiveness.&#xa0;</p>