The amorphous region of silk fibroin, with a loose structure and many amino acid residues containing active functional groups, is the main region of chemical reactions between silk and dyes and other substances. At present, the fastness of acid dyes commonly used in silk is not ideal to wet treatment. Although ideal fastness to wet treatment can be obtained for silk dyed with reactive dyes, reactive dyes are easy to be hydrolyzed, the utilization rate of dyes is low, and the structure of silk fibers is damaged by high temperature dyeing process. It is a low temperature dyeing method to dye cotton fibers with insoluble azo dyes combined with naphthol. There is a high content of tyrosine residues in silk protein, and it is found that diazo salt and tyrosine residues can be coupled, which makes silk achieve covalent bonding reaction with color diazo salt without adding other coupling components. Due to the limitation of the thermal stability of diazo salt, the previous studies on diazo salt dyed silk have adopted the method of mixing and using, which is inconvenient to operate. Therefore, the preparation of diazo salt with certain storage stability is conducive to the industrial application of the method.To solve the problems of traditional dyeing of silk, such as low fastness to wet treatment and high energy consumption at high temperature, we studied the energy-saving dyeing method of silk with high fastness to wet treatment. Tetrafluoroboric acid diazonium color salts corresponding to yellow GC and bright red GGS were prepared and separated successfully with yields of 72.24% and 70.89%. The chemical structure of the synthesized diazonium color salts was verified by ~1H-NMR and FT-IR. By measuring the UV-visible absorption spectra of diazonium salt solution and diazonium color salt solution under different storage methods, the absorbance change rates of diazonium color salt were analyzed, and results show that the absorbance change rate of diazo solution for three days is 94.5%, that of diazonium color salt for three days in solution form is 20.7%, and that of diazonium color salt for three days in solid form is 3.5%, which proves that the synthesized diazonium color salt has good storage stability. It was found by referring to the application of insoluble azo dyes on cotton fabrics, and adding chromophenol AS as another coupling component that o-chlorobenzene diazonium color salt and silk in situ coupling dyed fabric was yellow(λmax=400 nm; L*a*b: 76.6, 27.2, 86.4), the result of the coupling dyeing of the silk fabric after dipping phenol AS was orange-red(λmax=500 nm; L*a*b: 57.8, 67.3, 63.9), 2, 5-dichlorobenzene diazonium color salt and silk in situ coupling dyed fabric was yellow(λmax=440 nm; L*a*b: 65.6, 35.4, 75.1), and the result of the coupling dyeing of the silk fabric after dipping phenol AS was orange-red(λmax= 440 nm; L*a*b: 58.1, 65.1, 64.6). By comparing the results of cotton and silk coupling dyeing, the mechanism of diazonium color salt coupling alone or in the presence of Naphthol AS on silk was revealed. Therefore, stable diazonium tetrafluoroborate can be used to dye silk at room temperature, and the washing and rubbing color fastness of colored silk fabrics are all over grade 4. The research supplies a new method for energy saving and high quality dyeing methods of silk.Poor color fastness to wet treatment of silk products is a technical problem that has not been well solved at home and abroad. In recent years, the chemical activity of active functional groups in silk protein has been utilized to propose and study the dyeing method of silk with high wet fastness, and optimize the application conditions of the method. At the same time, the study also provides inspiration for future research. Based on the active functional groups of silk protein, chemical reactions are designed, and new methods of combining dyes with silk protein are found to realize industrial application and solve technical problems in the industry. [ABSTRACT FROM AUTHOR]