The invention relates to a fluorescent probe and a preparation method thereof in the technical field of 
biology, particularly to a fluorescent probe targeting MUC1 of in-vivo 
ovarian cancer tissue, and the preparation method of the fluorescent probe. The fluorescent probe targeting MUC1 of the in-vivo 
ovarian cancer tissue consists of an 
antibody against the MUC1, Cy5.5-n-hydroxy 
succinimide, and a 
fluorescein NHS dye. Because the fluorescent probe adopts double marks of the near-
infrared fluorescent dye cy5.5 and the 
fluorescein NHS, which are respectively suitable for in-vivo detection and ex-vivo detection; the MUC1 is I type 
transmembrane glycoprotein which expresses in various kinds of tissue, organ epithelial cells close to lumens, or glandular cavity surfaces, presents top end 
secretion and is in extreme distribution, and the expressing quantity of the MUC1 in 
cancer cells is obviously increased. Researches prove that 
ovarian cancer cells highly express the MUC1, and therefore, the MUC1 can be used as an ideal target for the treatment of ovarian 
cancer; the fluorescent probe targeting the MUC1, which is combined with double marks, can completely realize the specificity imaging of the ovarian 
cancer of a 
living body, so that real-time tracking in operations is completed.