Flavonoid glycosides are the main active constituents of Epimedii Folium and its related plants. They can be divided into polyglycosides and low glycosides according to the number of glycosyl group. The polyglycosides of Epimedii Folium can be transformed into low glycosides after biotransformation ；pharmacological activities of low glycosides in anti-tumor ，tonifying kidney yang and anti-osteoporosis are stronger than those of polyglycosides. In this paper ， the research progress about biotransformation technology of flavonoid glycosides of Epimedii Folium was reviewed. It was found that the main biotransformation pathway of flavonoid glycosides of Epimedii Folium was to obtain low glycosides by removing glycosyl group ； related methods were mainly enzymatic hydrolysis and microbial transformation ，and also included plant cell transformation ，acid hydrolysis method and synthesis method.