Abstract: To address the urgent need for low-cost, low-power implementation in polarization-agile systems, this paper proposes and designs a polarization converter based on a rotating zigzag-structured polarization grid. This design modulates the polarization state of incident electromagnetic waves through the mechanical rotation of a circular-shaped polarization grid, achieving low cost and low power consumption while effectively suppressing gain fluctuations during modulation. Detailed electromagnetic simulation studies were conducted on the proposed zigzag-type polarization grid model. Simulation results demonstrate that as the polarization grid rotates, the modulated polarization state traces a continuously varying, approximate figure-eight trajectory on the Poincaré sphere, confirming its flexible polarization control capability. This work provides an effective new solution for achieving low-cost, low-power, flexible polarization control using a passive metasurface, showing promising application prospects in fields such as polarization-domain electronic countermeasures.