A novel design project of bi-direction thrust torsion coupling was put forward for 2D electro-hydraulic proportional directional valve by using spherical roller, the wedge’s linear motion could be translated into spools rotary motion, and the output torque and 2D spool’s torsion angle could be amplified. On the basis of the mathematical model, the dynamic characteristic of thrust torsion coupling and the hysteresis characteristics due to backlash were analyzed by using phase-plane analysis method. The backlash was overcome by using dither compensation technology and the effect for eliminating the backlash was achieved. Based on the mathematical model and the prototype, the relationship between linear motion of the wedge and rotation angular displacement of the spool was researched and simulated. Simulation and experimental results were consistent. Experimental results showed that the hysteresis of backlash could be reduced efficiently by using dither compensation technology, the hysteresis was about 3.7% as dither amplitude was half of backlash, and it could be controlled below 2%, as dither amplitude was beyond the backlash. Bi-direction thrust torsion coupling could be used in the 2D electro-hydraulic proportional directional valve and the amplification of the displacement could be realized. 