The invention discloses a novel lignans compound and a preparation method and medical application thereof, belongs to the field of medicine, and particularly relates to a novel lignans compound separated from dried nandina leaves, and a preparation method and medical application thereof. The compound is reported for the first time, can be obtained by carrying out extraction, separation and purification on the dried nandina leaves, and is high in purity. In-vitro tests prove that the compound has the protective effect on H2O2 oxidative damage cells, has the antioxidation activity of scavenging free radical and active oxygen, and can be further researched and developed to be medicine for blood vessel protection.