The present invention relates to the application of N-azidoacetyl-D-mannosamine derivatives in the detection of esterase. The present invention mainly relates to N-azidoacetyl-D-mannosamine derivatives shown in the following formula (I) and their preparation methods and applications in the detection of esterases: wherein, R 1 is selected from H, F, Cl, Br, I, -OH, -NH 2 ,-NO 2 ,-N 3 , C 1‑6 Alkyl, C 1‑6 Alkoxy, ‑CO‑C 1‑6 Alkyl, ‑CO‑NH‑C 1‑6 Alkyl, -COOC 1‑6 Alkyl, aryl, aryloxy, heteroaryl, heteroaryloxy, heterocyclyl, heterocyclyloxy; said aryl, aryloxy, heteroaryl, heteroaryloxy , heterocyclyl, heterocyclyloxy are optionally substituted by the following groups: F, Cl, Br, I, -OH, -NH 2 ,-NO 2 ,-N 3 , C 1‑6 Alkyl, C 1‑6 Alkoxy; R 2 , R 3 The same or different, independently selected from O, S, NH, NMe; n 1 , n 2 The same or different, independently selected from an integer of 1-4; representing a bond or e bond.