The invention discloses an efficient fertilizer helpful for raising nitrogen utilization rate of spinach. The efficient fertilizer comprises the following ingredients: melatonin, a water-soluble silicon fertilizer, humic acid, mannoproteins, yeast, soybean curb residue, alga residue, high temperature calcined oyster shell porous powder, nanometer black bone charcoal, oxidized sodium alginate, a proper amount of mineralized small molecular activated water, etc. By using melatonin, the water-soluble silicon fertilizer, mineralized small molecular activated water and nanometer black bone charcoal, a nitrogen utilization promoter is prepared. Small molecular water-soluble silicon powder participates in cell metabolism to promote synthesis of an amino acid substance from a nitrogen substance. Melatonin accelerates photosynthesis and metabolism of plants and promotes utilization of nitrogen and oxalic acid. Thus, enrichment of nitrogen and oxalic acid by spinach is minimized and efficient cultivation of spinach is realized. Meanwhile, in cooperation with a nutrient solution processed with mineralized small molecular activated water and main materials, the fertilizer of the invention has rich nutrients and can effectively minimize enrichment of nitrogen and oxalic acid in spinach and raise quality of spinach.