The invention relates to equipment and method for producing directly reduced iron (DRI) in a gas-based vertical furnace by directly utilizing coal gasification hot coal gas. The method comprises the following steps: preparing synthetic gas by utilizing coal powder, water steam and oxygen gas, wherein the ratio of H2 to CO is 1.2 to 1.7 and the temperature is not greater than 850 DEG C after heat-exchanged and dust-removed furnace-top coal gas of the vertical furnace is added; carrying out dust removal; carrying out modification and removing CO2 and H2S at the temperature of 1100 to 1250 DEG C,with the help of a furnace material of a modifying furnace, wherein the temperature of modified coal gas is 900 DEG C to 1100 DEG C and the ratio of the H2 to the CO is 1.2 to 1.7; mixing the heat-exchanged and dust-removed furnace-top coal gas of the vertical furnace to obtain synthesized modified coal gas with the temperature of 850 DEG C to 900 DEG C; after removing dust of the synthesized modified coal gas, introducing into a vertical furnace with iron ore to obtain the DRI. According to the method provided by the invention, characteristics of energy resources of China are combined; coalgasification and gas-based vertical furnace direct reduction technologies are combined, and the dependence of a gas-based direct reduction method on natural gas is overcome; a long and complicated procedure of cooling the coal gasification hot coal gas, transforming, purifying and re-heating, and then producing the directly reduced iron by utilizing the coal gasification hot coal gas in the vertical furnace is avoided; the method provided by the invention has the advantages of short flow, low energy consumption, good reduction components, low pollution and the like.