The invention relates to a supported iron-based Fischer-Tropsch catalyst. The supported iron-based Fischer-Tropsch catalyst contains a spherical mesoporous carbon support, an active component iron located on the support and an optional catalyst promoter, wherein the specific surface area of the spherical mesoporous carbon support is 500-1000 m<2>/g, pore volume is 1.5-3.5 cm<3>/g, and average porediameter is 9-30 nm. According to the catalyst, spherical mesoporous carbon with high pore volume and large pore diameter is taken as the support, not only can high loading capacity of iron be realized, but also when the prepared catalyst is applied to the Fischer-Tropsch reaction, high Fischer-Tropsch reactivity and high productivity can be obtained, and particularly, CO conversion rate is remarkably increased and hydrocarbon productivity is improved. The invention further relates to preparation of the catalyst and an application of the catalyst to the Fischer-Tropsch reaction.