NOVELTY - A two-stage Fischer-Tropsch reactor system comprises a reactor (10) and a reactor (20). The reactor (10) contains iron catalyst for increasing conversion rate of synthesis gas. A synthesis gas (a) extracted from coal, biomass, or natural gas is supplied to reactor (10) and reacted with iron catalyst, to obtain synthesis fuel. The reactor (20) contains iron-cobalt catalyst or cobalt catalyst. A synthesis gas (b) discharged after the reaction from the reactor (10) and reacted with iron-cobalt catalyst or cobalt catalyst, to obtain synthesis fuel.    USE - Two-stage Fischer-Tropsch reactor system is used for producing synthetic fuel.    ADVANTAGE - The two-stage Fischer-Tropsch reactor system improves the conversion ratio of synthesis gas.    DETAILED DESCRIPTION - A two-stage Fischer-Tropsch reactor system a reactor (10) and a reactor (20). The reactor (10) contains iron catalyst for increasing conversion rate of synthesis gas. A synthesis gas (a) extracted from coal, biomass, or natural gas is supplied to reactor (10) and reacted with iron catalyst, to obtain synthesis fuel. The reactor (20) contains iron-cobalt catalyst or cobalt catalyst. A synthesis gas (b) discharged after the reaction from the reactor (10) and reacted with iron-cobalt catalyst or cobalt catalyst, to obtain synthesis fuel. The composition ratio of hydrogen to carbon monoxide in reactive gas (a) in the reactor (10) is 0.6-1.2. The inside temperature, pressure, and flow velocity of the synthesis gas (a) are adjusted such that, the carbon monoxide conversion rate is 50-80%. The composition ratio of hydrogen to carbon monoxide in reactive gas (b) in the reactor (20) is 1.8-2. The inside temperature, pressure, and flow velocity of the synthesis gas (b) are adjusted such that, the carbon monoxide conversion rate is 90-95%.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic structure of two-stage Fischer-Tropsch reactor system.    Reactors (10,20)    Inlet tube (11)    Heat exchanger (31)    Collection tank (33)    Lines (40,41,42)