Dendrobium (scientific name: Dendrobium nobile Lindl), also known as dendrobium rhyme, immortal grass, revival grass, purple lingering fairy plant, spider orchid, linlan, forbidden life, golden hairpin flower, etc. Stems erect, fleshy and thick, slightly flattened cylindrical, 10-60 cm long and 1.3 cm thick. Medicinal plant, sweet and slightly salty in nature, cold in nature, returns to the stomach, kidney and lung meridians. Yiweishengjin, nourishing yin and clearing heat. It is used for yin injury and fluid deficiency, dry mouth and polydipsia, retching due to lack of food, deficiency heat after illness, and dark eyesight. Dendrobium flower is elegant, exquisite and lovely, with bright colors and fragrant smell.

The whole drying process is about 18~20 hours. The whole drying process is divided into five sections. The drying steps are as follows:

In the first stage, the temperature is set to 45°C, the relative humidity of drying is set to 10%, the drying time is 6 hours, and the drying mode is used.

In the second stage, the temperature is set to 50°C, the relative humidity of drying is set to 10%, the drying time is 5 hours, and the drying + dehumidification mode is used.

In the third stage, the temperature is set to 65°C, the drying relative humidity is set to 10%, the drying time is 4 hours, and the drying + dehumidification mode is used.

In the fourth stage, the temperature is set to 70°C, the relative humidity of drying is set to 10%, the drying time is 3 hours, and the drying + dehumidification mode is used.

In the fifth stage, the temperature is set to 75°C, the drying relative humidity is set to 10%, the drying time is 1 hour, and the drying + dehumidification mode is used.