With the rapid development of integrated farming of tilapia, various metabolic diseases such as nutritional fatty liver disease are becoming increasingly serious. Severe fatty liver can cause liver failure and cause death in tilapia. It is particularly important to understand the mechanism of lipid metabolism in patients with fatty liver disease. Zebrafish, as a model animal for developmental biology research, is also a research hotspot for liver disease models. Stearoyl-CoA desaturase (SCD) is a key rate-limiting enzyme for MUFA, which plays an important role in regulating hepatic lipogenesis, fatty acid metabolism, and lipid oxidation. Therefore, it is important to study the regulatory mechanism of the scd gene in lipid metabolism in fish. In this study, the complete scd cDNA sequence of GIFT was cloned by RACE and qRT-PCR was used to analyze tissue expression characteristics. To verify the function of scd, an scd knockout zebrafish model was constructed using CRISPR/ Cas9 technology, and the phenotypic and gene expression changes of F3 mutants were studied, and the response mechanism of zebrafish lipid metabolism after scd deletion was verified in combination with high-fat diet experiments. The results showed that the cDNA full-length sequence of the scd gene of GIFT was 1,333 bp in length, including 173 bp at the 5′-UTR, 152 bp at the 3′-UTR, and a 1,008 bp open reading frame (ORF) encoding 335 amino acids. The scd gene was expressed in all tissues of male and female GIFT, with the highest expression in the liver and the lowest expression in the spleen. An scd knockout zebrafish model was constructed using CRISPR/Cas9 for functional validation, and the SCD^(–/–) zebrafish had a significantly enlarged abdomen compared to the SCD^(+/+) zebrafish. Western blot and qRT-PCR results showed that scd gene expression was significantly lower (P＜0.05) in zebrafish from the SCD^(–/–) group compared with zebrafish from the SCD^(+/+) group, and SCD protein expression abundance was also significantly lower (P＜0.05) in zebrafish from the SCD^(–/–) group. Under high fat dietary feeding, the red lipid droplets in the liver tissue cells of zebrafish in the HFD+SCD^(–/–) group were significantly reduced compared to those in the HFD+SCD^(+/+) group. The qRT-PCR results showed that scd mRNA expression was significantly lower in zebrafish in the SCD^(–/–) group compared with zebrafish in the SCD^(+/+) group after scd knockdown (P＜0.05), while lpl, fas, and hsl mRNA expression were significantly higher in the liver of zebrafish in the SCD^(–/–) group (P＜0.05). Compared with the zebrafish fed the control diet, zebrafish fed with the high-fat diet had significantly increased expression of scd mRNA in liver and inhibited the expression of fas mRNA (P＜0.05). The results also suggest that scd gene knockdown can alleviate liver fat deposition in zebrafish caused by high fat diets, and that the scd gene may play an important role in fatty acid metabolism and lipid synthesis in fish.