Synthetic seed of biological technology has been suggested as an effective strategy to improve breeding. Nano-TiO2 is a photosemiconductor material widely used in life science and agriculture. Nano-TiO2 has been recently shown to improve photosynthetic function, promote plant growth and development,but the physiology mechanism is still unclear. The aim of the current study was to confirm whether or not nano-TiO2 synthetic seed has an effect on germination and physiology of Dendrobium officinale. Using D. officinale protocorm models, we demonstrate that appropriate nano-TiO2 leads to growth and development of germination seedlings, and improves the root activity, nitrate reductase activity and antioxidant system activity. Our data also provide a basis for the improvement of the preparation process and practical production of D. officinale synthetic seeds.