Herein,　we　designed　the　tyrosinase　specific　sensing　probe　NITYO　with　recognition　unit,　3-hydroxy　benzyloxy,　that　also　regarded　as　an　electron-rich　group　that　quenches　the　naphthalimide　core　by　PET　effect.　When　tyrosinase　exists　and　catalyzes　the　secondary　oxidation　of　NITYO,　the　fluorescence　emission　goes　red　shift　with　＂turn-on＂　signal.　We　hypothesized　and　confirmed　these　results　through　comprehensive　analysis　such　as　molecular　orbital　analysis,　molecular　docking　and　HRMS.　To　sum　up,　we　achieve　the　tyrosinase　detection　by　NITYO　with　highly　sensitivity　and　selectivity.　It　can　be　used　in　food　samples　and　in　vivo　bioimaging.　Besides,　NITYO　performs　superb　linear　fitting　and　lower　detection　limit　(0.33　U/mL)　within　the　range　of　10-400　U/mL.