The present invention relates to a naphthol/graphene/bipyridinium electrochemiluminescence sensor preparation method and an application thereof to determining cyproheptadine hydrochloride. The methodis characterized in that: a Nafion membrane method is used to fix graphene and bipyridylium on a gold electrode, and electrochemiluminescence of cyproheptadine hydrochloride is detected; the result isa high voltage of 850 V of a photomultiplier tube and a scan rate of 0.1 V/s; a boric acid buffer solution with pH=7.5 is used; the luminescence intensity of the cyproheptadine hydrochloride standardin the concentration range of 1x10-7 to 6x10-5 mol/L satisfies the linearity; and the adding standard recovery of cyproheptadine hydrochloride is between 99.7% and 104.9%. The method provided by thepresent invention has good sensitivity and stability for testing cyproheptadine hydrochloride, and has a good effect; and compared with the bare electrode, by using the method, the utilization efficiency of bipyridylium can be improved, environmental pollution can be reduced, and a test cot can be saved, and the method has important significance for expanding the application of electrochemiluminescence in drug analysis.