The present invention is characterized by that using improved Vacin and went culture medium, adding BA3 + 0.15% active carbon + 1% banana + 2% cane sugar (relative to volume of culture medium, i.e. adding 0.15 g of active carbon and 1 g of banana in 100 ml of culture medium), temp. is 26 deg. C, light intensity is 1200 LX, daily lighting 16 hr, and using exophytic materials of stem top (1-2 mm), leaf and tender stem of iris so as to obtain fairly ideal result in cultivation of original bulbiform body of iris, and attain the goal of greatly raising propagation coefficient and reducing cost, and provide good condition for industrial cultivating seedling of iris.