The invention discloses a low-cost high-efficiency flower fertilizer. The low-cost high-efficiency flower fertilizer comprises soy bean dreg powder, straw powder, a surfactant, aged rice powder, chlorothalonil, alfalfa root, deionized water, and saccharomycetes. Beneficial effects of the low-cost high-efficiency flower fertilizer are that: cost is low; the used waste materials are cheap and easily available; a preparation method is simple, composite cost is extreme low; fertilizer efficiency is high; and it is shown by contrastive analysis that the low-cost high-efficiency flower fertilizer possesses excellent adaptability; and effects are better when the low-cost high-efficiency flower fertilizer is used for culturing cacti such as nopalxochia, crab cactus, rattle stick dance, cactus, and echinopsis tubiflora.