A preparation method of cosmos nutrient fertilizer, which is composed of: Houttuynia cordata powder, pine leaf powder, Achyranthes knuckle powder, chicken manure powder, duck manure powder, pigeon manure powder, rapeseed straw powder, cottonseed husk powder, sorghum Straw powder, rapeseed cake powder, peanut cake powder, corn leaf powder, plant ash powder, broad-leaved wood chips, pumpkin stem and leaf powder, pine needle powder, tea dry powder, neem leaf powder, garlic powder, ginger powder, the percentages are Percentage by weight; the various nutrients contained in the formula promote the grown cosmos leaves to be fat, thick and tender, dense in growth, strong in growth, good in light reception, rich in color in the corolla, bright and eye-catching, majestic and magnificent, with excellent landscape effects .