The invention discloses an iron base catalyst used for Fischer-Tropsch synthesis and a preparation method and the application thereof. The catalyst comprises iron, reducing auxiliary agents of IB family
metal Cu and / or Ag oxides, electronic auxiliary agents of IA family
metal Li, Na, K or Rb, hydrogenation auxiliary agents of VIII family
noble metal Ru, Rh, Pd or Pt and structural auxiliary agents of SiO2. The preparation method of the catalyst comprises the following steps: using alkaline compounds for carrying out fast
coprecipitation on
iron salts or a mixture of the
iron salts or reducing auxiliary agents of IB family
metal salt solutions; carrying out secondary pulping after precipitate washing; adding IA family metal salt solutions and silica
sol, or adding IA family metal
silicate in the pulp; carrying out
spray drying forming on pulp; then, soaking obtained materials in VIII family
noble metal salt solution; and obtaining the catalyst of the invention after
drying roasting. The catalyst is applicable to the technical process for producing
hydrocarbon through low-temperature Fischer-Tropsch synthesis reaction, and has high heavy
hydrocarbon product yield, wherein the
methane selectivity is very low, and the olefin selectivity is also obviously reduced.