Planar　single　degree　of　freedom　(DOF)　6-bar　mechanisms,　characterized　by　simple　control　and　high　stiffness,　find　extensive　applications　across　various　robotic　systems.　Nevertheless,　the　augmented　quantity　of　design　variables　presents　challenges　in　mechanism　design,　particularly　when　confronted　with　multiple　constraints.　This　paper　presents　the　implementation　of　computeraided　design　for　a　single　DOF　6-bar　mechanism.　Considering　the　characteristics　of　the　6-bar　mechanism,　a　classified　kinematics　modeling　method　is　proposed.　Subsequently,　a　constraint　index　system　is　established,　encompassing　trajectory,　posture,　performance,　and　additional　auxiliary　variable　constraints.　A　Monte　Carlo　layered　optimization　method　is　then　proposed.　The　introduction　of　the　constraint　scaling　coefficient　divides　the　optimization　process　into　multiple　layers,　wherein　the　constraint　conditions　are　dynamically　adjusted　at　each　layer.　The　Monte　Carlo　method　is　integrated　to　screen　initial　values　and　determine　the　number　of　variables　in　each　iteration,　facilitating　efficient　optimization　of　the　mechanism　under　multiple　constraints.　Building　on　this　foundation,　mechanism　design　software　is　developed　to　diminish　reliance　on　experience.　Numerous　examples　demonstrate　the　rapid　acquisition　of　6-bar　mechanisms　satisfying　multiple　constraints　through　the　proposed　method,　showcasing　exceptional　computational　efficiency.　This　study　serves　as　a　reference　for　different　users　seeking　to　accomplish　the　efficient　design　of　6-bar　mechanisms.