The flexible parallel mechanism has a broad application prospect in many fields such as medicine, robotics, precision manufacturing, military and construction, etc. However, the current six-degree-of-freedom(6-DOF) flexible parallel mechanism has increased the complexity and cost of the system due to the complexity of control caused by its strong coupling. Therefore, this paper starts from the perspective of reducing the coupling of the parallel mechanism, and launches a comprehensive study on the weakly coupled flexible parallel mechanism type, to explore a new type of parallel mechanism with efficient motion performance and stable structure. By applying the synthesis method of mechanism, the organic combination of weakly coupled characteristics and high-precision motion is realized by combining the redundant driver flexible parallel mechanism as a sub-module. Firstly, the design principle and performance of the two-transfer-one-rotation (2T1R) and two-rotation-one-translation (2R1T) redundant driver flexible parallel mechanisms are systematically investigated. Subsequently, according to the synthesis method of weakly-coupled flexible parallel mechanism, combined with the determination principle of shared flexible hinge, the weakly-coupled characteristics of multiple combined mechanisms are successfully constructed and evaluated. Finally, various new weakly-coupled flexible parallel mechanisms are synthesized, and a new 4-PPSP 6-DOF weakly-coupled flexible parallel mechanism is selected to verify the weak coupling properties and degrees of freedom.