Cannabis is a traditional industrial crop that has been used for thousands of years for medicines， foods， and textiles. Due to its active components， cannabis has attracted extensive attention in the pharmaceutical industry at home and abroad. Currently， 55 countries around the world have legalized medical marijuana， and two provinces in China， Yunnan and Heilongjiang， can legally cultivate and process industrial hemp. However， the low content of cannabidiol （CBD） in industrial hemp is not conducive to subsequent development and research. Based on this， the author took medicinal cannabis， defined by CHEN Shilin′s team as tetrahydrocannabinol （THC） content<0.3% and high CBD content， as the research object， and reviewed four aspects of the active ingredients of medicinal cannabis， the isolation and purification technology of CBD， the development and application of cannabinoid-related products and the breeding methods of medicinal cannabis. Through combing， it is suggested that subsequent research should focus on excavation of genes of CBD synthesis， molecular breeding of evolutionary cannabis by gene editing technology， development of green extraction process， discovery of more active ingredients， and high yield of CBD through synthetic biology and cell-free system， with a view to provide reference for the development and application of medicinal cannabis in China.