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A type of SCARA parallel mechanism with double parallelogram branches was proposed, which included four identical branches and had the advantages of compact structure, high bearing capacity and stiffness. Firstly, the topological structure and degree of freedom of the mechanism were described based on Lie group theory. Secondly, the closed-loop vector equation was constructed to derive the forward/inverse position solution, and two numerical examples were used to verify the correctness of the position solution. By deriving the closed-loop vector equation with respect to time, the Jacobian matrix of the mechanism was obtained, and the mapping relations between the input angular velocity and the end output velocity, and between the input angular acceleration and the end output acceleration were established, and the numerical simulation analysis was carried out. Then, based on the inverse position solution, the limit boundary search method was used to solve the workspace of the mechanism, and the corresponding atlas was drawn for analysis. In order to clarify the rotation performance of the moving platform of the mechanism, the spatial distribution maps of the maximum and minimum rotation angles of the moving platform under different working planes were drawn. On this basis, the dimensional homogeneous Jacobian matrix was constructed with the help of characteristic factors, and the motion transmission performance of the mechanism was analyzed by two methods of condition number and operability. Based on the direct and indirect Jacobian matrices, three kinds of singular positions of the mechanism were analyzed systematically, and the conditions of singularity occurrence were clarified. Finally, the correctness and feasibility of the theoretical analysis and design results were verified by simulation experiments with Matlab and ADAMS software. The research result can provides theoretical basis for the subsequent optimization and prototype manufacturing of the SCARA parallel mechanism in future.