Thanks to the microstructure, perfect antigen identification and bacteriophage selection, nanobody exhibits high affinity, high specificity, strong penetrability, and prones to genetical modification and expression. With completely available sequence, nanobody can be stably produced with high quality by recombinant expression in vitro, avoiding the inter-batch difference in traditional antibody production. With its unique physical and chemical stability, nanobody, as a new research tool, promises to be used in antibody drug research, basic medical research, diagnosis and treatment of diseases such as cancer and infectious disease.