ObjectiveTo sort out the historical evolution， prescription evolution and modern clinical application of Huagaisan. MethodHuagaisan and its synonym Huagaitang are used as keywords to search the databases of Traditional Chinese Medicine Think Tank， Chinese Medical Dictionary， Airusheng Chinese Medical Database and China National Knowledge Infrastructure（CNKI）. According to the inclusion and exclusion criteria， we obtained the information of ancient books and modern clinical research literature related to Huagaisan， and systematically reviewed and analyzed the historical origin， prescription composition， preparation method， dosage， efficacy， medicinal material origin， processing method and modern clinical application of Huagaisan. ResultA total of 198 pieces of ancient book information were included， involving 93 ancient Chinese medicine books. Huagaisan was composed of fried Perillae Fructus， red Poria， fried Mori Cortex， Citri Eoxcarpium Rubrum， stir-fried Armeniacae Semen Amarum， Ephedrae Herba and fried Glycyrrhizae Radix et Rhizoma， which had the efficacy of promoting the lungs and relieving epidemiological symptoms， expelling phlegm and relieving cough， and treating cough with wind-cold bundled epidemiological symptoms and stagnation of phlegm and Qi. The preparation method was suggested as boiling powder， crushing the seven herbs into coarse particles， the dosage of each drug was fried Perillae Fructus of 1.27 g， red Poria of 1.27 g， fried Mori Cortex of 1.27 g， Citri Eoxcarpium Rubrum of 1.27 g， stir-fried Armeniacae Semen Amarum of 1.27 g， Ephedrae Herba of 1.27 g and fried Glycyrrhizae Radix et Rhizoma of 0.64 g， taking 8.26 g when decocting， adding 300 mL of water， decocting to 210 mL， removing the dregs， and taking it warmly after meals. Twenty-one clinical research papers were included to analyze the modern clinical application of Huagaisan， which was mainly used in the treatment of respiratory diseases such as pneumonia， asthma， bronchitis and so on. ConclusionThis paper has verified and summarized the key information of the famous classical formula Huagaisan， which can provide a detailed reference basis for the development and clinical application of its compound preparation.