From the perspective of early textiles protection, this article analyzes a large number of domestic and foreign literature materials in this field. By comparing the conventional system analysis methods of fabrics and combining with modern scientific and technological methods, the types of fiber, types of dyes and dyeing processes of traditional costumes were measured and analyzed. Faced with the severe situation of the preservation of dyeing textiles of the costume museum in the late Qing Dynasty. In this study, FT-IR was used to identify the material of garments, and the dyes on textiles were extracted by extraction method. The Lab values of color of the textile surface before and after extraction were analyzed by a reflection spectrophotometer. The structure of dyes was analyzed by high-pressure liquid chromatography and mass spectrometry (LC-MS) to determine the structural components of dyes. To further study traditional costumes, we integrated modern analysis techniques (LC-MS) and concepts (Lab system) into traditional research, used objective science and technology to obtain more effective data and information and then support the conclusions obtained by subjective observation methods, which makes up for the gaps in this research field. Compared with traditional methods of textile identification, the relevant information obtained by modern scientific and technological methods is more detailed and reliable. It is advantageous to provide targeted preservation measures according to the characteristics of different dyes and different fibers, which is of great significance to the protection and preservation of the museum’s collection textiles. Aiming at the special needs of dyeing textiles in the late Qing Dynasty, it is necessary to carry out targeted preservation measures according to different dyestuff characteristics. In order to identify the dyes on a female red coat which may be produced in the late Qing Dynasty, the textile material was analyzed by FT-IR spectroscopy. The results indicated that it was silkworm silk fabrics. A method for extracting dyes from fabrics was established. Acetone, acetonitrile, pyridine/water (1/1, W/W), N,N-dimethylformamide (DMF), 0.1% ethylene diamine tetraacetic acid (EDTA)/DMF (1/1, W/W) and methanol were used to extract the dye from the sample and using the reflection spectrophotometer to compare the color measurement of the color of the textile surface and the color after peeling. In addition, it was found that adding a small amount of EDTA when extracting the dye would increase the stripping efficiency, so the dyeing method might be a mordant method, and EDTA might destroy the complexation between the dye and the mordant metal ion. The color appearance of the textile was measured by using a spectrophotometer, and the extracted dyes were analyzed by LC-MS technology. It was found that the water solution of pyridine had the best extraction effect for the dye. The results of LC-MS analysis indicated that the coat’s red color could be mainly matched by many dyes, and the main one of the dyes might be berberine (yellow) according to the way of dyeing onto the fabric and the same molecular weight. After verification by standard berberine dyes, it was proved that one of the dyes was berberine.