Abstract: To meet the development requirements for large aperture, high-packing-ratio, and light-mass deployable antennas, a novel ring deployable antenna mechanism based on a multi-stage parallel scissor mechanism was proposed. Firstly, the overall design, composition, and deployment principle of the mechanism were outlined and a freedom analysis of the rib units was conducted. Secondly, mathematical models were established for key structural dimensions, a three-dimensional model was constructed, and a driving cable routing scheme was designed. Kinematic simulation studies of the mechanism were performed using simulation software to analyze the motion patterns. Finally, prototype development and experimentation were conducted to validate the deployment principle. The research results indicate that the mechanism exhibits excellent synchronization during the deployment process with interference-free and sticking-free phenomena, and can achieve motion transition from stowed state to deployed state, verifying the correctness and feasibility of the structural scheme and operational principles. Through hierarchical linkage and constraint optimization, the multi-stage parallel scissor mechanism balances high-packing-ratio and high-synchronization, providing a configuration reference for large-aperture space antenna design.