Iron-based catalyst for Fischer-Tropsch synthesis of heavy hydrocarbon and its preparation method

The invention relates to an iron-based catalyst for Fischer-Tropsch synthesis of a heavy hydrocarbon and its preparation method, and mainly provides a solution to the problems that: as Fischer-Tropsch synthesis reactions in existing technologies are strong exothermic reactions, the use of a fixed bed can results in difficult reaction heat removal, easy temperature runaway, and easy deactivation of a catalyst; while the use of a fluidized bed can lead to low selectivity of a heavy hydrocarbon. The catalyst of the invention adopts at least one oxide selected from Si or Al as a vector, and a composition with a chemical formula of Fe100AaBbCcDdOx in atomic ratio as an active component. Specifically, A is selected from at least one of an alkali metal or an alkaline earth metal; B is at least one of La or Ce; C is at least one of Cu or Mn; and D is at least one of Cr, Mo, V, Zr or W. The technical scheme for the iron-based catalyst of the invention solves the problems well, and can be used in the industrial production of fluidized bed Fischer-Tropsch synthesis reactions.