Covalent organic frameworks(COFs) are a novel kind of crystalline organic polymer constructed with monomers via covalent bonds.COFs possess some properties such as large specific surface areas,good thermal and chemical stability,predictable control of structures and functions,etc.Based on the outstanding properties,COFs have a wide range of applications in gas storage,drug delivery,proton conduction and heterogeneous catalysis.The diverse structures and abundant functional groups also make COFs attractive in separation science including chromatography and sample pretreatment.COFs and their composites have been employed as potential sorbents for solid phase extraction,magnetic solid phase extraction and solid phase microextraction.In addition,COFs have been used as new stationary phases for gas chromatography,high performance liquid chromatography and capillary electrochromatography.The latest progress of COFs in separation science in the past 3 years has been summarized in this article,specially highlighting the key advancements of COFs in sample pretreatment such as aqueous media,food matrices,biological samples and offering a comprehensive overview in separation of organic molecules including chiral and isomeric compounds.This review also provides a reference and outlook for further exploration on the applications of COFs.