The invention discloses an efficient compound fertilizer for greening flowers and a preparation method thereof. The compound fertilizer is prepared from the following raw materials in parts by weight: 40-50 parts of human excreta, 15-25 parts of peony seed meal, 10-15 parts of coffee grounds, 20-30 parts of corn meal, 10-15 parts of peanut meal, 12-16 parts of chestnut shell, 18-24 parts of melon peel, 5-10 parts of gleditsia sinensis powder, 4-8 parts of hoof powder, 3-6 parts of illite powder, 5-10 parts of kieselguhr, 10-15 parts of alcohol waste liquid, 17-23 parts of ammonium hydrogen carbonate, 10-15 parts of ammonium sulfate, 14-18 parts of calcium dihydrogen phosphate, 3-6 parts of potassium humate, 8-16 parts of modified attapulgite, 4-6 parts of jade powder and 3-5 parts of ochre powder. The compound fertilizer is reasonable and scientific in raw material proportioning, contains nutrients required by the growth of the greening flowers, is quick in response and long and comprehensive in fertility, has high activity and long fertility of organic fertilizers and biological fertilizers, fast-acting property of inorganic fertilizers and specificity of bacterial manures, promotes the photosynthesis of plants, greatly increases the utilization rate and the fertility, can also improve the ecological environment of the flowers, inhibit diseases and insect pests of soil and improve the soil structure, and can be widely applied to fertilization management of the greening flowers.