The invention discloses a preparation and identification method for exosome in nasal cavity washing liquid for non-diagnosis application. The method includes steps of: collection of nasal cavity washing liquid, extraction and purification of the exosome, electron microscope identification of the exosome, and Western blotting detection for existence of proteins CD9 and CD63. The method is simple and available, is convenient and effective and achieves extraction of the exosome in nasal cavity washing liquid. The method is accurate and reliable and overcomes the defects of background impurity interference, low recovery rate of the exosome, and low quantity of identification proteins in the prior art. In addition, the method can be directly applied to subsequent detection and has great promotion and application values in scientific research.