Elastic torsion deformation often occurs in the supporting arms of shielding during fast opening and closing. A dynamic model that can describe this torsional elastic deformation is proposed based on the distributed parameters method. Then, a lumped-distributed model of the integral shielding system is built in light of the lumped-parameters-description method of the driven and transmission mechanism. Finally, the structural parameters of the supporting system are optimized using the multi-objective nonlinear constrained algorithm. The experimental results show that the mechanical resonance of the system is constrained, and the torsion resonance frequency of the supporting arms increased by 60%. The position error of the target actuator decreases to 8 μm thanks to vibration reduction at the base of the shielding.