The aim of this paper is to investigate the effect of microbiological method extraction of fermented Polygonatum sibiricum polysaccharides on the improvement of blood lipid levels and intestinal flora in mice with high-fat diet． Firstly，the cholesterol and cholate sorption experiments were carried out to evaluate the in vitro lipid-lowering capacity of Polygonatum sibiricum extracted by hot water extraction and microbiological method，and fermented Polygonatum sibiricum polysaccharides ( FPSP) extracted with the microbiological method which has better in vitro lipid-lowering capacity was used for animal experiments． The results of in vivo studies show that FPSP can significantly reduce the body weight，fat index，liver index，serum TC，TG，LDL-C levels，increase HDL-C levels，and significantly inhibit TNF-α and IL-6 release ( P ＜ 0. 05) ． High-throughput sequencing technology analysis finds that，after the intervention of FPSP，the total relative abundance of Firmicutes and Bacteroidetes in mouse feces increased in the phylum level; at the genus level，the relative abundance of probiotics such as Lactobacillus and Barnesiella relatively increased，and the relative abundance of pathogenic bacteria such as Clostridium XIVa，Helicobacter，Streptococcus，and Alistipes decreased． The above results show that Polygonatum sibiricum polysaccharides can improve the blood lipid level of high-fat diet mice and regulate the intestinal flora disorders．