The invention relates to an oral spray for inflammatory diseases of the oral cavity and a preparation method thereof. The oral spray comprises the following components: 0.1-5% of water-soluble chitosan, 0.5-5% of propolis extract, 0.1-1% of lactoferrin, 0.01-0.5% of lactoperoxidase, 0.1-0.5% of lysozyme, 0.01-0.1% of immunoglobulin, 1-10% of bovine colostrum extract, 1-10% of anti-caries sweetener, 0.8-1.2% of cold aromatic, 0.1-1% of preservative and the balance of water for injections. The preparation method is characterized by mixing the components, stirring uniformly, filling into an oralsprayer, and sterilizing at 85 DEG C for 15 minutes to obtain the finished product. The oral spray has the effect of immediately and rapidly treating inflammatory diseases of the oral cavity and the functions of resisting bacteria and viruses, relieving pains, reducing gum inflammation and blooding, promoting the healing of oral ulcer wounds, treating acute and chronic pharyngitis, moistening andfreshening the oral cavity and removing halitosis. The oral spray has the advantages of simple and convenient large-scale production process and no environmental pollution in the production process.