The invention discloses an isosorbide 5-mononitrate nasal drug delivery composition for treating coronary heart diseases and angina, and a preparing method thereof. The nasal drug delivery composition comprises isosorbide 5-mononitrat, a solvent and a preservative, and optionally comprises an absorption enhancer, an osmotic pressure regulator and other pharmaceutic adjuvants. The composition has simple preparing process and stable and controllable quality, and is suitable for industrial production. The preparation is quickly absorbed, takes effect in 3-5 minutes, achieves the maximum drug effect after 15 minutes, has high bioavailability, convenient use, and good compliance of patients, is especially suitable for delivering drugs to the middle and old patients, dysphagia patients and bedrid patients, is suitable for delivering drugs for patients with coronary heart diseases and angina in acute attach period at the first time, obtains valuable time for rescuing patient lives, and has significant clinical meaning on long-term continuous prevention and maintenance therapy.