A CD47 single-domain antibody and use thereof, and in particularly, a blocking type single-domain antibody for integrin-related protein (CD47) and derivative proteins thereof. In particular, disclosed are an integrin-related protein (CD47) binding molecule and use thereof, particularly in the treatment and/or prevention, or diagnosis of CD47-associated diseases, such as tumors. The CD47 single-domain antibody involved can effectively block the interaction between CD47 and a ligand SIRPa thereof, has good binding activity, blocking activity, affinity and stability, can effectively enhance the phagocytosis of tumor cells by macrophages, and shows significant anti-tumor activity in both a human lymphoma model and a human ovarian cancer model. In addition, the antibody does not cause hemoagglutination in vitro, and shows excellent safety in cynomolgus monkeys.