Provided is an efficient energy-conserving and environment-friendly coal-fired boiler control system. Pre-burning desulphurizing and dewatering treatments are conducted on coal with exhaust afterheat and a microwave technology, excessive pure oxygen is adopted to help the burning of the coal in a burner during combustion, temperature, pressure, flow and concentration are effectively and precisely controlled during reaction, air is replaced by the excessive pure oxygen, the total quantity of burning gas is reduced by 70%-80%, and the excessive pure oxygen burns to make the burning rate of fuel reach the highest limit value instantaneously and effectively; a sulfur and nitrogen element in the coal experiences pre-burning, in-burning and post-burning treatments, burning exhausts with different temperatures are sprayed with ammonia and ammonium hydroxide to achieve total desulfurization and denitration, and escaping ammonia gas is absorbed through a bubble-cap column. The efficient energy-conserving and environment-friendly coal-fired boiler control system has the advantages that microwave desulphurizing and dewatering are conducted before the coal is burned by utilizing reclaimed exhaust energy, the exhaust complementary energy is recycled, dewatering improves the effective energy conversion of the coal, and the excessive pure oxygen burns to make the discharge of harmful substances of oxynitride, sulfide, oxysulfide, carbonic oxide, benzene, organic matter of long carbon chain macromolecule and the like reduced, which is energy-conserving and emission-reducing.