According to the design theory for parallel mechanisms (PMs) based on position and orientation characteristic (POC) equation and the principle for coupling degree reduction, a novel 3T1R PM with lower coupling degree was proposed. Firstly, the structure coupling-reducing optimization design for a kind of 3T1R PM was performed, whose POC and degree of freedom were unchanged with lower coupling degree (κ1=1 and κ2=0).Moreover, the topological structure and the decoupling characteristic were analyzed and the results showed the motion of the mechanism was partially decoupled. Secondly, the positive and inverse analytic solutions were analyzed, and the singularity analysis was also performed based on Jacobian matrix, from which two singularity-free workspace regions were obtained. Finally, the workspace and rotation capability were also analyzed, which showed that workspace and rotation capability of the coupling reduction PM were enhanced compared with that of the original PM under the same structural parameters. The results showed that the coupling reduction mechanism had good motion-decoupling property, simple mechanical structure, large workspace and remarkable consistent rotational capacity in full workspace, and avoided the shortcomings of bad rotational capacity and strong coupling, which made it a promising prospect in the application of industry.