The zebrafish xenograft model plays an important role in cancer modelling, especially breast cancer xenografts. This model facilitates the real-time observation of tumor cell growth, metastasis, and interactions with the immune system, thus providing novel insights and experimental foundations for breast cancer treatment. Furthermore, the zebrafish xenograft model offers a valuable tool for high-throughput drug screening. This review provides an overview of the contributions of the zebrafish xenograft model to elucidating the mechanisms underlying breast cancer development, and its use in screening anti-tumor drugs and conducting therapeutic research.