In this paper， the name， origin， medicinal parts， producing area， harvesting， processing methods and efficacy of Equiseti Hiemalis Herba（EHH） in famous classical formulas were examined by reviewing related ancient and modern literature. Through textual research， Muzei was first appeared in Zhenyuan Guanglifang（《贞元广利方》）， and used as a mainstream name by later generations. It is also known by other names， such as Cuocao and Bigancao. The main origin of ancient EHH was Equisetum hyemale， which was mixed with E. ramosissimum during the Qing dynasty. The medicinal part was the above-ground part of EHH. In ancient times， the genuine producing area was considered to be Qinzhou， which is now Tianshui city， Gansu. In modern times， EHH produced in Liaoning province is believed to be of higher quality. Currently， the main producing area of EHH circulating in the market is the northeast region in China. EHH with stems that are thick and long， a green color， a thick texture， and clearly visible edges and roughness， but without any easily separating joints being considered the best. The processing methods of the past dynasties mainly included filing， removing knots， stir-baked the crude drugs into black on outside and brown in inside， urine soaking， sun drying and shade drying. In modern times， the main processing method is to first moisturize the plant material， and then cut it into sections before drying. In terms of medicinal properties， EHH is considered by both ancient and modern medicine to have a neutral nature， a slightly sweet and bitter taste， and is non-toxic. Its primary therapeutic effects are related to treating eye diseases， intestinal wind bleeding and uterine bleeding. Based on the research， it is suggested that the dried above-ground part of E. hiemale be used in the development and utilization of famous classical formulas. For the processing requirements are not indicated， it is suggested using raw decoction pieces as medicine， and the processing method refers to the 2020 edition of Chinese Pharmacopoeia. If it is clearly stated that fried charcoal is required， it is recommended to refer to general requirements 0213 of the 2020 edition of Chinese Pharmacopoeia， if it is clearly stated that removing knots is required， it is recommended to follow the ancient method.

This article systematically analyzes the historical evolution of the name， origin， producing area， quality evaluation， harvesting and processing， clinical efficacy of Pyrrosiae Folium by consulting the ancient materia medica， medical books and prescription books， combined with modern literature， in order to provide a reference for the development of famous classical formulas containing this herb. After herbal textual research， it was found that the names of Pyrrosiae Folium in the past dynasties were mostly derived from its color， shape and efficacy. And there were other nicknames such as Shizhe， Shipi and Shilan. Song， Yuan dynasties and before the period， the main origin of Pyrrosiae Folium was Pyrrosia petiolosa， in the Ming dynasty， the main origins were P. petiolosa and P. sheareri， during the Qing dynasty to the present， the main origins were P. sheareri， P. petiolosa and P. lingua. Anciently， the respected Dao-di production area of Pyrrosiae Folium was the area of Lianyungang city， Jiangsu province. In modern times， Anhui and Zhejiang provinces are the main producing areas of P. sheareri， Fujian and Taiwan provinces are the main producing areas of P. lingua， and Guizhou and Hubei provinces are the main producing areas of P. petiolosa. In ancient and modern times， Pyrrosiae Folium with large leaves and thick texture is considered to be the best， the medicinal part is the leaves， and the harvesting and processing methods recorded in the past dynasties were mainly shade-drying after harvesting in the February and July of the lunar calendar， while the modern ones are mostly harvested throughout the year. The processing methods of the past dynasties mainly included removing fuzz by scraping， lightly roasted， frying， fat-fried. However， in modern times， it is mostly used the raw products as a medicine after cleaning， cutting and drying. In ancient times， Pyrrosiae Folium was thought to have a neutral nature with slightly sweet and bitter taste， while in modern times， it is thought to have a slightly cold nature with slightly sweet and bitter taste， and the main effects in ancient and modern times are diuretic， clearing lung-heat， hemostasis and so on. Based on the research results， it is suggested that P. sheareri， P. petiolosa and P. lingua can be used as the medicinal base， processing method can be according to the requirements of formulas， and if the processing requirements are not indicated， the raw products can be selected as the medicine.