The invention belongs to the technical field of extraction and purification of 
plant ingredients and particularly relates to a method for extracting and purifying 
cannabidiol from China-hemp. In the method, an ingredient of 
cannabidiol is extracted from floral leaves in a mature period of the China-hemp according to a supercritical CO2 extraction technique, a 
cannabidiol extract is further purified by macroporous adsorbent resin and a rapid purification 
system, a cannabidiol content of an obtained product is 98% or higher, and the cannabidiol product does not contain a psychotoxic ingredient 
tetrahydrocannabinol. According to the method, a chemical 
organic solvent is not used in an extraction process, so that the method is environment-friendly and is low in 
toxicity and high in efficiency; the loss of cannabidiol in an adsorption 
elution process is reduced in a purification process, so that the 
impurity ingredients such as 
tetrahydrocannabinol and the like are effectively removed, and the use of an organic regent is decreased, so that the purification cost is lowered, and the environmental 
pollution is reduced. The product is high in yield and purity, and the requirement for development of a value-added product of the China-hemp, in particular to the market requirement of the 
active ingredient of the cannabidiol product in the China-hemp, can be met, and especially, the cannabidiol product has the great application 
advantage in the pharmaceutical field.