The invention mainly relates to the field of traditional Chinese medicine planting and discloses an underwood planting method of crocus sativus. The method comprises the steps of seeding in spring, top application after flowering and corm digging; the method is easy, the forest is a deciduous forest, the illumination of underwood soil can be changed along with seasons, corms of the crocus sativus are sowed in spring, sunlight is sufficient, the temperature is suitable, so that germination of the corms of the crocus sativus is promoted, the germination time is shortened, and the germination rate reaches 100%; after flowers of the crocus sativus wither, tree leaves grow up, through transpiration of the tree leaves, the underwood temperature is lowered and suitable for growth of the crocus sativus, growth of tree roots can improve the mellowness of the soil, absorption of nutrient ingredients by root system of the crocus sativus is promoted, and the dormancy period after the flowers fall off is avoided; in the middle of March, after the flowers of the crocus sativus wither, a nutrient solution is sprayed, wherein the nutrient solution is rich in organic matter, inorganic matter and microorganism, promotes absorption, accelerates expansion of the corms, makes the growth period of the crocus sativus shortened to 150-160 days, and obviously lowers the planting cost.