GIFT is a type of freshwater farmed fish with high economic value and nutritional value. The liver is an important organ of fish metabolism. Once it is damaged or the disease occurs, it will lead to metabolic disorders and decreased disease resistance, and may cause other secondary diseases. In the high-density intensive culture of tilapia, the feed nutrition is not balanced, especially the addition of high-fat feed. High fat content can accelerate the growth of fish, but long-term feeding of high-fat diet can lead to metabolic disorders of fish, accumulation of fat in the body, easy to cause fatty liver, and ultimately death due to liver necrosis or hemorrhage, seriously affecting the breeding benefits. The main purpose of this study was to investigate the effects of apple peel added to feed on liver fat metabolism and fat deposition in tilapia tilapia use transcriptomics to analyze related signal regulation pathways, focusing on fat metabolism and inflammatory response and finally screening differentially expressed genes. The development of this study is helpful to understand the molecular mechanism of apple peel extract powder-mediated liver fat metabolism and inflammatory response in GIFT, and relieve liver stress. It also provides theoretical support for the application of apple peel extract powder as a feed additiion in aquatic products. Overall design: we selected liver samples of the control group (C), the optimal group of apple peel extracted powders supplementation (0.2%, APE_A) and the high dose group of apple peel extracted powders supplementation (0.8%, APE_H) for transcriptome sequencing.