The steam and KOH activation methods were used to activate lignin based carbon fibers. The original and activated carbon fibers were applied to prepare three kinds of nickel based catalysts. The characterization results illustrated that the KOH activated carbon fibers (KACF) possessed the best surface structural parameters. The tests for catalytic performance showed that the catalyst supported on the KACF was the greatest in the steam reforming of methane. Based on that, the catalysts with different metal content were prepared to obtain an optimal content, which possessed the greatest catalytic activity. The catalyst of 5% metal content supported on the KACF was proved to have the highest methane conversion rate and syngas selectivity. And the optimal catalyst was applied for the steam reforming of methane. The CH4 conversion ratio could reach more than 90%. The influence of catalyst dosage, reaction temperature and the molar ratio of H2O/CH4 was investigated. The results indicated that the ratio of hydrogen to carbon monoxide could be adjusted by the temperature and the ratio of H2O/CH4. Higher temperatures could increase the ratio of H2/CO, while the excess steam decreased it. Besides, the carbon deposition experiment of methane decomposition with the catalysts of 5% Ni/SKACF and 5% Ni/γ-Al2O3 proved that the catalyst prepared by carbon fiber support has great properties for carbon deposition resistance.