Metformin　(MET)　is　currently　the　first-line　treatment　for　type　2　diabetes　mellitus　(T2DM).　However,　overdose　and　long-term　use　of　MET　may　induce　a　serious　liver　injury.　What’s　worse,　diagnosis　of　MET-induced　liver　injury　remains　challenging　in　clinic.　Although　several　probes　have　been　reported　for　imaging　MET-induced　liver　injury　utilizing　upregulated　hepatic　H2S　as　a　biomarker,　they　are　still　at　risk　of　nonspecific　activation　in　complex　physiological　environments　and　rely　on　light　excitation　with　limited　imaging　depth.　Herein,　we　rationally　designed　and　developed　a　dual-locked　probe,　DPA-H2S,　for　precise　imaging　of　MET-induced　liver　injury　by　H2S-activated　sonoafterglow　luminescence.　DPA-H2S　is　a　small　molecule　consisting　of　a　sonosensitizer　protoporphyrin　IX　(PpIX)　and　an　afterglow　substrate　that　is　dual-locked　with　a　H2S-responsive　2,4-dinitrobenzene　group　and　a　1O2-responsive　electron-rich　double　bond.　When　employing　DPA-H2S　for　imaging　of　MET-induced　liver　injury　in　vivo,　since　the　PpIX　moiety　can　produce　1O2　in　situ　at　the　liver　site　under　focused　ultrasound　(US)　irradiation,　the　two　locks　of　DPA-H2S　can　be　specifically　activated　by　the　highly　upregulated　H2S　at　the　liver　injury　sites　and　the　in　situ　generated　1O2,　respectively.　Thus,　the　sonoafterglow　signal　of　DPA-H2S　is　significantly　turned　on,　enabling　precise　imaging　of　the　MET-induced　liver　injury.　In　vitro　results　showed　that,　through　H2S-activated　sonoafterglow　luminescence,　DPA-H2S　was　capable　of　imaging　H2S　with　good　sensitivity　and　high　selectivity　and　realized　deep　tissue　imaging　(∼20　mm,　signal-to-background　ratio　(SBR)　=　3.4).　Furthermore,　we　successfully　applied　DPA-H2S　for　precise　in　vivo　imaging　of　MET-induced　liver　injury.　We　anticipate　that　our　dual-locked　probe,　DPA-H2S,　may　serve　as　a　promising　tool　in　assisting　the　diagnosis　of　MET-induced　liver　injury　in　clinics　and　informing　the　clinical　utilization　of　MET　in　the　near　future.　©　2024　American　Chemical　Society.