•The dyes and mordants of ancient Chinese textiles were identified by multi-techniques.•For the first time Rhamnus davurica. has been detected in a textile sample.•The data of dyes and mordants combined with the ancient records can be successfully used to explore the ancient dyeing techniques. In this research, two pieces of textiles from the Qing dynasty (1644–1910) were studied to character the dyeing techniques using appropriate Eco-friendly analysis. The dye was identified by UHPLC-Q-Tof-MS, which improved sensitivity and resolution significantly when compared with LC-MS. The mordant in the textile dyeing process was determined by SEM-EDX. The results showed that Gardenia jasminoides Ellis was used in dyeing the yellow silk thread, Polygonum tinctorium was the source of the plant for the blue silk thread, and the plant source of green fabric most likely turned out to be Rhamnus davurica pall., which was first detected in ancient textiles. Iron and aluminum ions were detected as the metal ions in the mordant. Combined with all this information, the original dyeing process used for these textiles can be inferred. The results allow us to understand the dyeing techniques in the Qing dynasty, and to provide scientific support for conservation and restoration of the precious cultural heritage.