NOVELTY - Composite fertilizer comprises 25-35 wt.% urea, 30-40 wt.% calcium superphosphate, 10-20 wt.% potassium sulfate, 0.5-1 wt.% ammonium molybdate, 0.5-1 wt.% zinc sulfate, 1-3 wt.% borax, 0.3-0.7 wt.% sodium benzoate, 0.1-0.5 wt.% nanocarbon, 0.1-0.5 wt.% photosynthetic bacteria, 10-20 wt.% fermentation dregs powder and 4.0-4.5 wt.% white mud meal powder. The particle diameter of nanocarbon is less than or equal to 20 nm. The particle size of white mud meal powder is less than or equal to 1 mm. The fermentation dregs powder is Chinese medicine residue powder obtained after fermentation with particle size of less than or equal to 1 mm.    USE - Composite fertilizer for mustard (claimed).    ADVANTAGE - The product increases mustard yield and quality.    DETAILED DESCRIPTION - Composite fertilizer comprises 25-35 wt.% urea, 30-40 wt.% calcium superphosphate, 10-20 wt.% potassium sulfate, 0.5-1 wt.% ammonium molybdate, 0.5-1 wt.% zinc sulfate, 1-3 wt.% borax, 0.3-0.7 wt.% sodium benzoate, 0.1-0.5 wt.% nanocarbon, 0.1-0.5 wt.% photosynthetic bacteria, 10-20 wt.% fermentation dregs powder and 4.0-4.5 wt.% white mud meal powder. The particle diameter of nanocarbon is less than or equal to 20 nm. The particle size of white mud meal powder is less than or equal to 1 mm. The fermentation dregs powder is Chinese medicine residue powder obtained after fermentation with particle size of less than or equal to 1 mm. The content of photosynthetic bacteria is greater than or equal to 200000/mL. The photosynthetic bacteria liquid is the resulting fermentation broth of photosynthetic bacteria after treatment of liquid food waste. An INDEPENDENT CLAIM is included for preparation of composite fertilizer comprising crushing urea and calcium superphosphate into powder, mixing urea, calcium superphosphate, fermentation dregs powder, potassium sulfate, ammonium molybdate, zinc sulfate, borax, sodium benzoate, nanocarbon, white mud meal powder, stirring, granulating, uniformly spraying with photosynthetic bacteria liquid, cooling and drying.