The invention relates to a poly-generation technique for using
coal gas and
coke oven gas as raw materials. The poly-generation technique comprises the following steps of: carrying out mixing on part of H2 prepared by
purified water gas and
coke oven gas through
pressure swing adsorption and
tail gas obtained by Fischer-Tropsch synthesis, carrying out Fischer-Tropsch synthesis and obtaining
hydrocarbon mixture and
tail gas. The CO2 separated from
tail gas separate by first
pressure swing adsorption enters a
urea synthesis unit for reaction, the CO and the
hydrogen respectively obtained by separation of second
pressure swing adsorption and third pressure swing adsorption of the residual tail gas are circulated back to a Fischer-Tropsch synthesis unit for reaction; and the residual gases can be used for generating power or obtaining SNG by secondary condensation. The
coke oven gas enters pressure swing adsorption after being purified and desulphurized so as to separate H2; wherein one part of H2 is used as supplementation of H2 needed by Fischer-Tropsch synthesis and the other part of H2 is mixed with N2 for
ammonia synthesis so as to obtain synthetic
ammonia; and the synthetic
ammonia is mixed with CO2 obtained by the first condensation and CO2 separated from the Fischer-Tropsch synthesis for
urea synthesis so as to obtain
urea. The CO2 separated from the first condensation of
desorption gas by pressure swing adsorption of the
coke oven gas is used for urea synthesis; and the residual gases is treated by the second condensation to obtain SNG and
mixed gas of CO and N2. The invention has no emission of
greenhouse gases, uses richness in carbon and deficiency in
hydrogen of the
coal gas and the richness in
hydrogen and deficiency in carbon of the
coke oven gas to carry out
complementation, realizes modulation of product structure by Fischer-Tropsch synthesis and improves the economical efficiency of the process of Fischer-Tropsch synthesis.