disclosed is a bio - fertilizer composition for promoting growth of orchid plants . the composition comprises a symbiotic organism , a growth substance ; and a medium , which is used to mix and evenly disperse the symbiotic organisms and the growth substance . the symbiotic organism is selected from the group consisting of rhizoctonia sp . and rhizoctonia sp . . the bio - fertilizer composition according to the invention can promote the growth of orchid plants , increase the flowering rate and flowering quality , decrease the occurrence of root disease to prevent the usage of pesticide , and increase the beneficial components toward human health of medicinal orchids .