Carbon-coated Ni/SiO2 prepared by dry reforming of CH4 with CO2 was applied for the preparation of the cobalt-based Fischer-Tropsch synthesis (FTS) catalyst with 20 wt%Co to elucidate the metal-support interaction to FTS activity after carbon depositions on the Ni/SiO2. The deposited carbons on the reforming catalyst of Ni/SiO2, which were mainly in the form of filamentous or encapsulated carbons, largely increased CO conversion compared with the fresh Ni/SiO2 without a significant variation of hydrocarbon distributions. The deposited carbons on the Ni/SiO2 play an important role in increasing the reducibility of cobalt oxides due to a mitigated metal-support interaction. The enhanced catalytic activity during FTS reaction is mainly attributed to the proper modification of the Ni/SiO2 surfaces with encapsulated carbons on the exposed nickel surfaces, which largely alters the reducibility of cobalt oxides by reducing the interaction of cobalt particles with the carbon-coated Ni/SiO2 surfaces.