Abstract: At present, many parallel mechanisms with motion bifurcation characteristics use single-loop mechanisms. The mechanism is complex and the configuration is monotonous. There are few known parallel mechanisms with 3T1R and 2R2T multi-modes.A branch chain with motion bifurcation characteristics was introduced into the parallel mechanism, and a motion bifurcation parallel mechanism with 3T1R + 2R2T two modes was obtained, and its degree of freedom and motion bifurcation characteristics were analyzed by using the screw theory.The results showed that when the mechanism was at the motion bifurcation point, the moving platform had five degrees of freedom. By driving different driving pairs, the mechanism can evolve into a configuration with different motion bifurcation characteristics, including three movements and one rotation, two movements and two rotations. In order to realize the reasonable switching between the two configurations, a rigid drive method was used to select a reasonable drive pair. The forward and inverse kinematics solutions of the parallel mechanism in different configurations were analyzed. It was concluded that both the forward and inverse kinematics equations can be solved analytically. The mechanism had good motion decoupling. The correctness of the forward and inverse kinematics solution was verified by ADAMS. The singularity of the mechanism was analyzed by Jacobi matrix. The results showed that there was no singularity in the two motion modes in a reasonable working range. The workspace of the organization was drawn. Based on the motion/force transfer performance method, the performance index of the mechanism was analyzed, and the performance distribution map in the workspace was drawn. The results showed that the two configurations had good motion/force transfer characteristics, and the high quality workspace was large.