The invention discloses high-strength H-shaped steel for prefabricated buildings. The high-strength H-shaped steel is prepared from the raw materials including, by weight, 1,500-1,600 parts of iron ore raw material, 300-400 parts of coke, 120-160 parts of pulverized coal and 100-120 parts of a modified refining agent. The invention further discloses a production technology of the high-strength H-shaped steel for the prefabricated buildings. Through a bottom blowing mode, the smelting time can be shortened, the power consumption can be reduced, the desulfurization and dephosphorization conditions can be improved, the residual manganese content in the steel can be increased, the yield of the steel can be increased, the temperature uniformity of molten steel and the uniformity of components can be improved, and the quality of the steel can be improved; through cooperation of stirring and bottom blowing, the diffusion rate of reactants and products is increased, then the floating removal rate of inclusions is increased exponentially, and the quality of the steel is improved; through addition of the modified refining agent, the slagging effect and the slagging rate are increased, moltensteel impurities are adsorbed, the smelting cost per ton of steel is obviously reduced, phosphorus removal is facilitated, and the quality of the steel is improved.