Finding efficient,low toxicity,and pollution-free plant-based pesticides and drug substitutes from resource rich plants has become one of the current research hotspots.Walnut plants contain various active ingredients such as flavonoids,quinones,phenolic acids,and volatile oils.In recent years,many studies have extracted,isolated,and studied the pharmacological functions of chemical components from different parts of walnut plants,and found that they have various biological activities such as antibacterial,antioxidant,and anticancer.They are commonly used in clinical practice totreat cancer,and have antibacterial properties.This article reviews the chemical composition,pharmacological activity,and mechanism of different parts of walnut,in order to provide reference value for the development and utilization of walnut resources and the development of walnut source drugs.