Abstract Fischer Tropsch synthesis provides a non-petroleum pathway for the production of high value liquid fuels and long-chain alpha olefins from syngas. However, regulating product distribution to promote the formation of high value product while maintaining low selectivity for C1 by-products (CH4 and CO2) remains a significant challenge. Iron based composite catalysts were prepared via dual doping and modification, i.e., alkali metals and transition metals using mesoporous silica SBA-15 as the support. The catalyst was characterized by XPS, XRD, H2-TPR, CO2-TPD, TEM, Roman and other methods, and the relationship between the catalyst structure and catalytic performance was studied. At 1 MPa and 300 °C, The CO conversion rate of Fe–Zn–K/SBA-15 (30% − 10% 2%/100%) catalyst is 62.4%, methane selectivity is reduced to 4.6%, carbon dioxide selectivity is 32.6%, olefin ratio is 7.6%, and long-chain hydrocarbon C5 + selectivity is 62.8%.