For　complex　space　tasks,　the　gripper　is　expected　to　adapt　to　items　of　different　shapes　and　sizes;　it　has　the　advantages　of　simple　control　and　acceptable　force　adaptability.　Therefore,　a　one　degree　of　freedom　(DOF)　six-bar　space　gripper　with　good　task　adaptability　is　developed.　Design　constraints　are　analyzed　on　the　basis　of　typical　grasping　task　analysis.　A　design　method　based　on　proportional　coefficients　is　proposed,　considering　that　the　constraints　are　complex　and　the　six-bar　mechanism　has　many　design　parameters.　The　design　efficiency　can　be　improved　by　reducing　the　target　trajectory　according　to　proportional　coefficients.　The　one-DOF　six-bar　mechanism　that　satisfies　the　final　constraints　has　multiple　operation　modes　with　only　one　drive.　On　this　basis,　the　elastic　element　is　added　as　part　of　the　mechanism　rather　than　outside　the　mechanism,　and　a　rigid-flexible　coupling　mechanical　model　is　established　to　further　analyze　the　effect　of　elastic　element　on　the　force　adaptability.　Experiments　show　that　the　designed　one-DOF　gripper　can　grasp　cylinders　with　different　diameters　and　grasp　and　move　items　of　different　sizes　with　fingertips　under　different　space　constraints;　it　also　has　good　force　adaptability.　This　finding　provides　a　reference　for　reducing　the　complexity　of　gripper　and　improving　the　diversity　of　grasping　task.　(C)　2022　Elsevier　Masson　SAS.　All　rights　reserved.