This study aimed to investigate the therapeutic effects of magnolol on production performance in postpeak laying hens. We divided the hens into three groups (ND, MAG300, MAG500) and conducted a 10-week feeding trial. The results indicated that daily supplementation with magnolol improved the laying rate, reduced the feed-to-egg ratio, controlled liver fat accumulation, and alleviated ovarian oxidative stress and apoptosis. Additionally, 16S rDNA analysis revealed that magnolol increased microbial diversity in the cecum, augmented the abundance of beneficial bacteria, and diminished the abundance of harmful bacteria. Untargeted metabolomics of blood demonstrated that magnolol reduced the concentration of glycerophospholipid-related metabolites while increasing the levels of propionate and amino acid metabolites. Furthermore, liver transcriptome analysis indicated that magnolol inhibited fatty acid synthesis, transport, and elongation, while promoting fatty acid oxidation. These results collectively demonstrate that magnolol can positively regulate the gut-liver-ovary axis to enhance the production performance in laying hens.