GDF15, also known as growth differentiation factor-15, is expressed by multiple tissues and secreted into the serum. It regulates numerous physiological processes, such as affecting food intake and causing weight loss, by binding to the receptor GFRAL. Under normal physiological conditions, GDF15 levels are low; however, its expression significantly increases under pathological conditions such as diabetes and cancer. In some special types of advanced cancers, GDF15 levels can rise and trigger anorexia-cachexia syndrome. We created humanized B-hGDF15 mice by replacing the mouse GDF15 gene with the human GDF15 gene in situ. Additionally, we established a B-hGDF15 MC38 cell line by inserting an exogenous promoter and the human GDF15 CDS sequence at the mouse GDF15 locus in MC38 cells. RT-PCR was conducted to detect mRNA levels of hGDF15 in B-hGDF15 mice, confirming the absence of mouseGdf15expression and the presence of humanGDF15expression. We performed ELISA to detect the protein expression levels of hGDF15 in B-hGDF15 mice and B-hGDF15 MC38 humanized cell line, confirming successful expression of the hGDF15 protein. When B-hGDF15 mice were inoculated with B-hGDF15 MC38, tumor model was developed successfully, and a trend of body weight loss was observed compared with the wild-type MC38 group. Subsequently, we performed an efficacy experiment in B-hGDF15 mice inoculated with B-hGDF15 MC38. After 7 days of inoculation, the mice were grouped based on body weight and tumor size, and the treatment group received 10 mg/kg of a ponsegromab analog on the same day. We observed significant weight gain in the treated group compared to the control group, indicating that B-hGDF15 mice and B-hGDF15 MC38 provide an excellent preclinicalin vivo model for testing GDF15-targeted drugs.