The invention provides a boiler coal combustion-improving desulfurizing agent composition. The composition comprises the following components in parts by weight: 3-9 parts of sodium carbonate, 1-2 parts of sodium acetate, 3-9 parts of calcium carbonate, 4-9 parts of aluminium hydroxide, 2-5 parts of ferric trichloride, 3-10 parts of ferric oxide, 8-22 parts of potassium permanganate, 8-22 parts of potassium chlorate, 15-40 parts of activated attapulgite clay, 7-13 parts of manganese oxide, 4-8 parts of copper oxide, 4-8 parts of alumina, 3-8 parts of copper carbonate, 3-10 parts of zinc oxide, 3-10 parts of zinc nitrate, 4-11 parts of sodium dichromate, 0.5-1.5 parts of barium molybdate, 0.5-1.5 parts of vanadium pentoxide, 0.2-0.5 part of cerium oxide and 1-3 parts of dispersing agent JFC. The composition is an additive suitable for coal-fired boilers in the petroleum, chemical, power, thermoelectricity and metallurgy industries, can absorb and solidify sulfur dioxide generated in the combustion process, adsorbs dust and other harmful substances in quantity and simultaneously removes smoke dust scales and jelly adhering to the inner walls of combustors, thus inhibiting the concentration of flue gas emission.