Magnetorheological (MR) valves are widely used in hydraulic systems due to their fast response speed and stable pressure regulation. It is easy to increase the valve dimension size and block the fluid flow channel by changing the valve’s internal structure to improve the pressure drop. The multi-objective optimization of pressure drop and adjustable coefficient of the single coil radial flow MR valve was carried out. A single coil radial flow MR valve with magnetic isolation sleeve was designed. The working principle was expounded, and the mathematical model of pressure drop was also deduced based on Bingham model. Simulation model was established by using the finite element method, and the constraint conditions were established to analyze the influence of the dimension size on shear yield stress and pressure drop. The optimization of geometrical parameters of MR valve was carried out by using ANSYS zero-order and first-order optimization tools. The average magnetic flux density and pressure drop at the effective damping gap were simulated and compared. The pressure drop performance of MR valve was tested on the dynamic performance test rig. The experimental results showed that the pressure drop of the MR valve before optimization was 1.84MPa at the applied current of 1.8A, while after optimization was 2.58MPa, the increment was 40.22%. At the same time, the adjustable coefficient of pressure drop was 7.94 before optimization and 10.07 after optimization, which was increased by 26.83%. Moreover, the load cases had no influence on the pressure drop.