The invention discloses an industrial method for recycling desulphurized plaster and blast furnace gas in iron-making production. Fumes exhausted from a sintering machine generate the desulphurized plaster after passing through a limestone-plaster fume desulphurizing device. Blast furnace gas is used as a fuel, and the desulphurized plaster is calcined in a calcinator at a high temperature of between 1,000 DEG C and 1,250 DEG C. CaSO4 undergoes a decomposition reaction under the reducing atmosphere that the blast furnace gas is used as a reducing agent. The generated CaO is thrown back into the sintering machine as a fusing agent for the production of sintering ores; and SO2 in tail gas is used for the production of sulphuric acid. In the method, the blast furnace gas generated in the iron-making production is adopted as the reducing agent to decompose the desulphurized plaster; the generated CaO is thrown into the sintering machine as the fusing agent for the production of the sintering ores; and the SO2 in the tail gas is used for the production of the sulphuric acid. The industrial method simultaneously solves the problems of the recycling of byproducts-desulphurized plaster and the blast furnace gas in the iron-making production technique and the problem of environmental pollution; moreover, the industrial method can reduce production cost.