Soybean hull polysaccharide (ASP), a pectic polysaccharide with potential effects on regulating lipid metabolism through gut microbiota and their metabolites, was studied to explore its regulatory mechanisms. The study examined the alleviating effect of ASP on high-fat diet (HFD) zebrafish through histopathological examination and biochemical analysis. Additionally, the lipid-lowering mechanism was analyzed combined with metabolomics and the proliferation of gut microbiota. Results showed that ASP significantly ameliorated body weight and blood lipids and also reduced hepatic lipid accumulation and hepatic lipid peroxidation damage. Bioinformatics analyses showed that ASP administration (240 μg/day) generated significant gut microbiota structural changes in high-fat diet-fed zebrafish, in particular, reducing Proteobacteria and increasing Cetobacterium relative abundance levels. ASP upregulates propionic acid, linoleic acid, 6-hydroxyhexanoic acid, and l-threonine biosynthesis by mediating gut microbiota regulation of amino acid and lipid metabolic pathways. Utilizing a correlation network derived from Spearman's correlation coefficients, significant microbial phylotypes that react to ASP demonstrated a strong association with parameters linked to lipid metabolic disorders. Fecal metabolites (e.g. propionic acid) were positively correlated with gut microbiota (e.g. Cetobacterium) in the high-dose ASP group. Our results provide a theoretical basis for new ASP prebiotic formulations to target the gut microbiota and prevent lipid metabolic disorders.