Objective To explore the mechanism of electroacupuncture in improving lipid metabolism in polycystic ovary syndrome(PCOS)based on metabolomics combined with transcriptomics.Methods Eight-een SD rats were divided into the control group,the PCOS group and the electroacupuncture group,with 6 rats in each group.The PCOS group and the electroacupuncture group used intragastric letrozole to establish the PCOS model.After the model was established,the electroacupuncture group was intervened with electroacu-puncture,while the control group was only given sodium carboxymethyl cellulose by gavage.Observed the changes in body weight and estrous cycle of the three groups,detected the sex hormones,blood lipids,liver function,ovarian morphology,plasma metabolism and liver function indicators of the three groups.Metabolo-mics was used to analyze the differences in metabolites in plasma,the differences in gene expression in the liv-er were detected by RT-qPCR.Results Weight gain and estrous cycle disorder occurred in the PCOS group,and the ovarian morphology showed a thinning of the granulosa cell layer,with a significant reduction in the number of corpus luteum and mature follicles.Meanwhile,sex hormones were abnormal(total testosterone and androgen levels were increased,estradiol and progesterone levels were decreased),dyslipidemia occurred(TC,TG,LDL-C were increased,HDL-C level was decreased),and liver function was abnormal(AST,total protein,ALB,TBIL were increased).The electroacupuncture group significantly reduced weight.It improved the estrous cycle,and the granulosa cell layer of the ovary thickened,with a significant increasing in the num-ber of corpus luteum and mature follicles.Meanwhile,sex hormone levels were improved(androgen and total testosterone levels were decreased,estradiol level was increased),lipid balance(TC,TG,LDL-C levels were reduced,HDL-C level was increased)and liver function(AST,total protein,ALB,and TBIL levels were de-creased)was restored.Transcriptomics suggested that electroacupuncture down-regulated the expression of cytochrome P450(CYPs)family genes related to steroid hormones and lipid metabolism,and the results were confirmed by RT-qPCR.Combined omics analysis revealed that electroacupuncture might mainly exert its effect on improving lipid metabolism disorders in PCOS rats through the linoleic acid metabolic pathway.Con-clusion Electroacupuncture can regulate lipid metabolism in rats with PCOS.