The invention provides a boiler coal combustion-improving desulfurizing and denitrifying agent composition. The composition comprises the following raw materials in parts by weight: 2-7 parts of sodium carbonate, 1-3 parts of alumina, 2-8 parts of aluminium hydroxide, 2-5 parts of ferric trichloride, 2-6 parts of ferric oxide, 3-10 parts of potassium permanganate, 3-10 parts of potassium chlorate, 10-35 parts of activated attapulgite clay, 15-30 parts of urea, 2-4 parts of ammonium formate, 2-4 parts of ammonium chloride, 6-23 parts of ammonium acetate, 3-9 parts of manganese oxide, 9-12 parts of copper chloride, 1-3 parts of copper oxide, 2-4 parts of zinc sulfate, 1-3 parts of zinc nitrate, 7-18 parts of potassium dichromate, 1.0-1.5 parts of titanium dioxide, 0.5-1.0 part of barium molybdate, 0.5-1.5 parts of cobalt sulfate, 0.5-1.5 parts of vanadium pentoxide, 0.3-0.7 part of cerium oxide, 0.1-0.2 part of sodium dodecyl benzene sulfonate and 0.1-0.2 part of alkyl glyceryl ether. The composition is convenient to use, has stable properties, plays roles of combustion improving, desulfurization and denitrification, has coal saving rate of 8-25% and can remove fixed sulfur by 50-70%.