Process and system for preparing activated carbon by self-heating pyrolysis-activation of large waste wood

The invention relates to a process and a system for preparing activated carbon by self-heating pyrolysis-activation of large waste wood, the process comprises the following steps: crushing the large waste wood, then drying, feeding dried particles into a pyrolyzing furnace which adopts an indirect heating rotary kiln, and dividing pyrolysis products into two paths, wherein gaseous pyrolysis volatile components are fed into a gas burner, hot flue gas generated by combustion generates water vapor through a small-sized evaporator, then one path is fed into an activating furnace, and the other path is fed into a pyrolyzing furnace; solid pyrolytic coke is fed into the activation furnace, activated carbon is generated through coupling activation of water vapor and air, activated tail gas serves as fuel for reburning denitration of a pyrolytic volatile component combustor, the activated tail gas is fed at the rear section of the combustor, reduction of NOx is achieved by constructing a reducing atmosphere, and the