In　this　research,　double　perovskite　quantum　dots　Cs　2　AgInCl　6　:　Tb　3　+　/Sm　3　+　/Bi　3　+　are　synthesized　employing　a　hightemperature　thermal　injection　method.　The　temperature-dependent　emission　spectra　and　the　fluorescence　decay　curves　of　samples　show　the　quantum　dots　can　be　applied　to　dual-mode　temperature　sensing　employing　fluorescence　intensity　ratio　technique　(between　656　nm　(Sm　3　+　)　and　549　nm　(Tb　3　+　))　and　fluorescence　lifetime　thermometry　(549　nm　(Tb　3　+　)),　achieving　maximal　relative　sensitivities　of　3.24%/K　(351　K)　and　0.68%/K　(373　K),　respectively.　This　study　offers　valuable　insights　into　the　temperature　sensing　capabilities　of　these　quantum　dots,　which　shows　that　these　quantum　dots　are　promising　high-sensitivity　dual-mode　temperature　sensing　materials.