On-demand　designed　theranostics　nanoagents　show　promising　applications　for　next-generation　precision-and-personalized　oncotherapy.　Researchers　have　since　aimed　to　develop　nanoplatforms　that　can　efficiently　deliver　drugs　and　contrast　medium　to　tumor　and　release　active　ingredients　in　response　to　tumor　microenvironment　(TME)　conditions.　Herein,　we　propose　a　modular　strategy,　and　develop　a　series　of　nanoplatforms　based　on　metal-coordinated-polyprodrugs　for　cancer　theranostics.　The　polyprodrugs　were　synthesized　through　a　click-reaction　between　amino　acid　and　doxorubicin　(DOX)　with　dipropiolate.　The　backbones　of　the　polyprodrugs　had　intrinsic　sensitivities　to　pH　and/or　GSH,　and　provided　abundant　-COOH,　-NH2,　or　-S-S-　to　chelate　with　functional　metal　ions　and　further　self-assembled　to　form　different　morphologies.　Dicysteine,　which　contains　disulfide　bond　(-S-S-),　was　chosen　to　copolymerize　with　DOX　and　triethylene　glycol　dipropiolate　(TEP)　to　prepare　the　pH/GSH　dual-responsive　polyprodrug　poly(dicysteine-co-TEP-co-DOX)　(pDTD),　then　separately　coordinated　with　Gd3+,　Fe3+,　and　Mn2+　to　construct　nanoplatforms　pDTD@M　(M　representing　the　metal　ions).　In　vitro　and　in　vivo　investigations　suggest　the　metal-coordinated-polyprodrug　nanoplatforms　have　good　magnetic　resonance　imaging　(MRI)　ability　and　efficient　tumor-growth　inhibition　with　high　safety.　The　design　strategy　of　nanoplatforms　based　on　metal-coordinated-polyprodrugs　provides　a　new　idea　for　on-demand　construction　of　promising　theranostics　agents.　Statement　of　significance:　Compared　to　small　molecule　antitumor　drugs,　polymeric　drugs　have　high　drug　loading　ratio　and　are　easily　enriched　at　the　tumor　site　to　achieve　improved　therapy　efficacy.　This　work　utilizes　click　reactions　to　link　amino　acids　with　anticancer　drugs　to　produce　polymeric　drugs　that　are　degraded　in　response　to　tumor　microenvironment　and　released　small　molecule　antitumor　drugs　mainly　in　tumor　sites,　and　subtly　utilizes　the　coordination　of　amino　acid　to　chelate　MRI　functional　metal　ion　to　realize　enhanced　MRI　imaging　mediated　tumor　therapy.　This　strategy　provides　a　new　idea　for　the　convenient　construction　of　polymeric　drugs　for　tumor　theranostics.　©　2022　Acta　Materialia　Inc.