It　is　still　a　challenge　to　capture　radioactive　90Sr2+　ions　conveniently,　quickly,　and　efficiently　from　complex　aqueous　solutions.　Herein,　a　composite　material,　KInSnS4@CF　aerogel　(CF　=　collagen　fiber),　was　prepared　by　loading　the　metal　sulfide　ion　exchanger　KInSnS4　on　collagen　fibers　through　electrostatic　self-assembly.　The　KInSnS4@CF　aerogel　is　well　shaped　and　maneuverable.　It　can　efficiently　capture　Sr2+　with　satisfactory　adsorption　capacity　(qSrmax　=　41.48　mg　g−1),　fast　kinetics　(adsorption　equilibrium　within　2　min),　broad　pH　activity　(pH　=　2-12),　and　facile　elution.　The　aerogel　shows　good　selectivity　for　the　capture　of　Sr2+　under　the　coexistence　of　Na+,　Cs+,　Ca2+,　and　Mg2+,　as　well　as　in　actual　water　samples.　In　addition,　it　can　serve　as　the　stationary　phase　being　used　in　the　ion　exchange　column　for　the　efficient　treatment　of　Sr2+　solutions　in　a　dynamic　manner.　The　efficient　Sr2+　removal　of　the　KInSnS4@CF　aerogel　mainly　originates　from　ion　exchange　between　Sr2+　and　K+　in　the　interlayer　spaces　of　KInSnS4,　while　the　CFs　mainly　serve　as　support　materials.　This　work　not　only　provides　a　new　easy-to-operate　and　environmentally　friendly　metal　sulfide　composite　aerogel,　but　also　paves　the　avenue　for　the　application　of　CFs　from　leather　industry　waste.　©　2025　The　Royal　Society　of　Chemistry.