The invention relates to a production process of activated carbon. The production process of activated carbon comprises the following steps: 1, feeding a dried carbonized material to a furnace body through a furnace end feeder of a rotary activating oven, setting the temperature in the furnace body at 800-1000 DEG C, and arranging thermocouple temperature sensing devices and air blowers in front three sections of the furnace body; 2, introducing water steam to the furnace body to be reacted with the carbonized material, controlling the reaction time within 3-10 hours, and recovering tail gases generated by reaction through a tail gas recovery device arranged at the tail of the furnace, and then, mainly introducing the mixed gases in form of CO and H2 to the boiler which generates the water steam for combustion of the boiler; and 3, feeding the activated carbon obtained by reaction from a discharge port at the tail of the furnace to a discharge cooler to be cooled, and smashing, verifying, packaging and putting in storage. According to the production process of activated carbon provided by the invention, the yield is high, the product quality is good, the labor intensity is low, the production efficiency is high, and the process is energy-saving and environmentally-friendly.