The invention provides a fertilizer application method for promoting rapid growth of directly-sown seedlings in a bletilla striata greenhouse. The fertilizer application method comprises the followingsteps: preparation of bletilla striata seeds, construction of a greenhouse, soil preparation and film mulching, substrate laying and watering, sowing, watering and bacterial liquid spraying, construction of a small arch shed, EM bacterial liquid spraying, removal of the small arch shed, weeding and watering, fertilizer spraying, supplementary application of fertilizers, and transplanting. With the fertilizer application method for promoting rapid growth of the directly-sown seedlings in the bletilla striata greenhouse provided by the invention, the diurnal temperature of the small arch shed in the greenhouse is controlled in a range of 15 to 28 DEG C, so the temperature required for germination of the bletilla striata seeds on a seedbed is guaranteed; meanwhile, the humidity and microbialenvironment of the seedbed are controlled, so the environmental conditions required for germination and growth of the bletilla striata seeds are supplied; further more, different fertilizers are applied to bletilla striata seedlings at different time, so growth and development of directly-sown bletilla striata seedlings can be effectively and rapidly improved.