Diets rich in various active ingredients may be an effective intervention strategy for non-alcoholic fatty liver disease (NAFLD). The green pea hull (GPH) is a processing by-product of green peas rich in dietary fiber and polyphenols. Here, a mouse model of NAFLD induced by DSS + high-fat diet (HFD) was established to explore the intervention effect of the GPH. The results showed that dietary supplements with the GPH can inhibit obesity and reduce lipid accumulation in the mouse liver to prevent liver fibrosis. GPH intervention can improve liver antioxidant capacity, reduce blood lipid deposition and maintain glucose homeostasis. DSS-induced disruption of the intestinal barrier aggravates NAFLD, which may be caused by the influx of large amounts of LPS. A multi-omics approach combining metabolomics and transcriptomic analysis indicated that glycine was the key target and its content was decreased in the liver after GPH intervention, and that dietary supplements with the GPH can relieve NAFLD via the SHMT2/glycine/mTOR/PPAR-γ signaling pathway, which was further supported by liver-associated protein expression. In conclusion, our study demonstrated that dietary GPH can significantly ameliorate NAFLD, and the future development of related food products can enhance the economic value of the GPH.