Dendrobium is divided into ornamental and medicinal varieties due to ornamental and medicinal values. However, current research mainly focuses on medicinal Dendrobium, with less study on the medicinal value of ornamental Dendrobium. We analyzed the microstructures, active components of the stems from twelve ornamental Dendrobium, and explored the biosynthetic networks of these active components based on transcriptome sequencing. This study found the Dendrobium with the highest content of polysaccharide, alkaloid, and flavonoid was Dendrobium aphyllum (53.89 %), Dendrobium thyrsiflorum (2.11 %) and Dendrobium loddigesii (7.21 %). Further research revealed 9 DEGs associated with polysaccharide biosynthesis were highly expressed in D. aphyllum
4 DEGs related to alkaloid biosynthesis were highly expressed in D. thyrsiflorum
8 DEGs associated with flavonoid biosynthesis were highly expressed in D. loddigesii. This study revealed the potential medicinal value of ornamental Dendrobium and the synthetic mechanisms of its medicinal components, providing a foundation for the medical applications of ornamental Dendrobium.