Abstract: Disclosed are an OXM3 storage agent, an OXM3 formulation and a preparation method. The OXM3 storage agent comprises 0.5-5 mg/mL tromethamine, 0.1-100 mg/mL stabilizer, 0.01-5 mg/mL chelating agent and a solvent, wherein: the stabilizer comprises one or more of mannitol, propylene glycol, arginine, arginine hydrochloride, histidine and histidine hydrochloride, the chelating agent comprises edetate disodium, and the solvent comprises water. The OXM3 formulation prepared from the OXM3 storage agent can ensure that the active ingredient OXM3 is stably stored for at least 6 months, preferably for 12 months or more, and more preferably for 18-24 months or more.