The invention discloses a recycling device for hot gas of a distribution room of a thermal power plant. The recycling device comprises a circulating fluidized bed boiler; a primary air fan of the boiler and a secondary air fan of the boiler are arranged on the two sides of the circulating fluidized bed boiler correspondingly and are connected with air guide pipes; the other ends of the air guide pipes are connected with a plurality of branch pipes; the other ends of the branch pipes are inserted into the side wall of the distribution room in a penetrating mode; an inner cavity of each branch pipe is connected with an isolation valve and a fireproof valve; and air inlets are evenly formed in the lower sides of the walls of the distribution room. The hot gas inside the distribution room of the thermal power plant is introduced into a hearth of the boiler through the pipes to participate in oxygen-assisted combustion mainly by means of the primary air fan of the boiler and the secondary air fan of the boiler, wasted hot gas is fully recycled, natural ventilation of the distribution room is increased for cooling, the equipment expense and operation expense invested for cooling of the distribution room are saved, and the standard coal consumption of the boiler is greatly reduced due to increasing of the temperature of air inlet gas of the air fans of the boiler.