Objective: The extraction process and film-forming preparation technology of Huayu Xiaozhong spray film was optimized respectively by orthogonal design and central composite design / response surface method( CCD-RSM). Methods: With the extraction rate of amygdalin as the index,the orthogonal experiment was adopted for the optimization of extraction process. With the film-forming time,spraying effect,thickness and maintain time of spray film as the indexes,the dosages of PVA 1788,PVP k30 and glycerin as fact...