Ovarian failure in postmenopausal female leads E2 to dramatic decrease which is an important reason of menopausal dyslipidemia. PCSK9 as a secretory lipid metabolic regulator plays a critical role in the cholesterol metabolism by negatively regulating LDLR in hepatocytes. Clinical data showed PCSK9 was elevated and positively correlated with LDL-C in the blood of postmenopausal women. However, the relationship between E2 and PCSK9 and the role of PCSK9 in postmenopausal dyslipidemia are still unclear. In this research, 10-week-old ovariectomized mice were fed for 4 weeks with normal diet or high-fat diet, then tested the lipid metabolism profiles and PCSK9 in the blood and the expression of LDLR and PCSK9 in the liver. On this basis, PCSK9-/- ovariectomized mice were used to further verify the effect of PCSK9 in dyslipidemia of ovariectomized mice. Finally, the ovariectomized mice with high-fat diet were subcutaneous injected respectively with E2 or PCSK9 inhibitor alone or both together for 2 weeks and were tested as previous experiment. The results showed PCSK9, TC and LDL-c all increased in the blood of in WT ovariectomized mice and their PCSK9 is positively correlated with LDL-c, while there were on obvious lipid metabolism disorder in the PCSK9−/− ovariectomized mice. PCSK9 inhibitor increased the LDLR on the liver and ameliorated the dyslipidemia in WT ovariectomized mice. It suggests that PCSK9 plays an important role in the dyslipidemia of ovariectomized mice, which provides a new strategy for clinical diagnosis and treatment of the dyslipidemia in post-menopause.