<p>This study proposes a novel single-degree-of-freedom (SDOF) hexagonal mechanism that utilizes a cam mechanism to regulate its movement. The hexagonal mechanism adopts a conjugate cam as joint slideways, forming an internal closed-chain cam mechanism that is connected to an external 6R linkage via connecting links. By integrating the cam mechanism’s rotation with the driving system, the mechanism can achieve variable length of the central collinear cranks through coupling structure. Moreover, by utilizing the closed-chain cam mechanism and variable parameters of the central cranks, motion control and adjustment of the external structure with three degrees of freedom can be achieved by central driving with SDOF. On the basis of the locomotion planning and kinematics analysis, the structure design and parameter analysis of the hexagonal mechanism are presented. Moreover, the parameters are analyzed using the repeatability of joint trajectories on the basis of locomotion planning that reduces initial motion conditions, ensures motion continuity, and reduces collision energy loss. Finally, the rationality of the design of the hexagonal mechanism with dynamic rolling locomotion is verified through theory, simulation, and experiment.</p>