Abstract: The study focuses on a epiphytic 3-year-old Dendrobium violaceum from Quercus acutissima, the chemical constituents under 2 different cultivation modes were analyzed using ultra-high performance liquid chromatography-tandem mass spectrometry. The results showed that the total anthocyanin content of the 3-year-old epiphytic D. devonianum grown from Q. acutissima was higher than that of the 3-year-old D. devonianum grown in the artificial facility cultivation, but the total flavonoid content was lower. Combined with UPLC-MS/MS technique analysis, it was found that the change of cultivation pattern had the most significant effect on the biosynthesis of flavonoids as well as the biosynthetic pathways of flavonoids and flavonols. Among them, 11 differential metabolites showed an upward trend with the change of cultivation pattern, including rhizopodophyllin, apigenin, chanterellin(dihydrokaempferol), and poncirin−2″−O−glucoside, etc. The up-regulated substances were mainly related to the resistance of D. devonianum, and could increase the synthesis of the substances with protective and antistress effects in D. devonianum. Thirteen differential metabolites showed a decreasing trend with the change of cultivation pattern, including nerolidol, naringenin*, naringenin chalcone*, 3,5,7−trihydroxyflavanone(phragmitolone), etc. The down-regulated substances were mainly related to the effects of antioxidant, anti-inflammatory, anti-bacterial, anti-fibrotic, and regulation of apoptosis, etc. These results indicate that the composition of D. devonianum is closely related to the cultivation mode.