The work aims to prepare the optimal catalyst by synthesizing iron/activated carbon (Fe/C) and iron/graphene (Fe/G) and investigating the adsorption and degradation for the methylene blue dyes in the water with the catalyst prepared based on the afore-said synthesized materials. The adsorption and degradation ability of Fe/C and Fe/G at 20 ℃ and the influences of the amount of hydrogen peroxide on their degradation effect were discussed. The adsorption mode of Fe/C and Fe/G was researched and the kinetic parameter was calculated. When Fe/C and Fe/G of the same mass and with different iron contents were used to adsorb the methylene blue solution of the same initial concentration, and the adsorption effects of pure activated carbon and pure graphene were the best; however, their catalytic and degradation ability would be enhanced with the increase in iron content. When the mass fraction of iron was 20%, Fe/C and Fe/G were the optimal catalysts and their adsorption for methylene blue conformed to Freundlich equation model, prone to multilayer adsorption. The activation energy of iron (20%)/graphene to catalyze and degrade hydrogen peroxide was greater than that of iron (20%)/activated carbon in effect. The activation energy in the system can moderately avoid exceedingly fast decomposition of hydrogen peroxide, thus increasing the time to act upon the methylene blue and improving the catalytic and degradation ability of the system.