The invention discloses a naphthalene bridged annular n-heterocyclic carbene silver complex, a preparation method thereof and an application of the complex. 1, 8-diaminonaphthalene reacts with chloroacetyl chloride in an organic solvent, and an obtained product (W) reacts with N-ethylimidazole to obtain a product (Y). The product (Y) reacts with silver oxide to obtain the annular n-heterocyclic carbene silver complex (1). The complex (1) serves as a subject, different types of nitrates serve as objects, the subject and the objects are dissolved in the organic solvent at the temperature of 25 DEG C, subject solution is mixed with different object solution at a certain concentration, fluorescence spectra are measured, and the objects recognizable by the subject are found out. The subject istitrated by different-concentration objects recognizable by the subject, and the fluorescence spectra of the subject are measured. The annular n-heterocyclic carbene silver complex has the advantagesof simplicity in preparation and obvious fluorescence sensing effect, can be used for manufacturing a fluorescent molecular recognition system and can be applied to the field of fluorescent chemistry.