Bio-barcode technology, as a new diagnostic tool, has been gradually applied to the detection of proteins, nucleic acids, and small-molecule compounds. Based on the sandwich structure of gold nanoparticles and using magnetic field effects, the bio-barcode technology aims to amplify the signal after eluting numerous oligonucleotides of the same sequence on the surface of gold nanoparticles and complete the detection of the target directly and indirectly. In this study, the principle and application of bio-barcodes are introduced, and the joint application of bio-barcode and biochip silver-dyeing technology, enzyme-labeled gold nanoscale technology, biosensor technology, microplate silver-dyeing technology, and polymerase chain reaction technology are reviewed. Considering the future outlook of this technology, it is of great significance to explore the best reaction conditions, optimize the operation procedures, explore the residue detection of a variety of substances, and develop standardized and commercial immunity kits for bio-barcode technology in the future.