The invention discloses a novel indoor fire-fighting device with a fire extinguishing function. The novel indoor fire-fighting device with the fire extinguishing function comprises a fire-fighting room, an air purification room, a communication chamber, a water storage tank and a reaction room. The device is used for extinguishing fire by utilizing the principle that sodium bicarbonate and aluminum sulfate react to produce a large number of carbon dioxide gases; the reaction chamber is arranged for separately storing the two substances; the sodium bicarbonate is stored in a second storage box;a servo motor is arranged at one end of the second storage box; when a temperature sensor detects that the indoor temperature is too high, a programmable logic controller (PLC) automatically judges that a fire breaks out, and the servo motor runs at the moment, so that a sodium bicarbonate solution in the second storage box is poured into a first storage box so as to be mixed with an aluminum sulfate solution, and a large number of generated carbon dioxide gases enter the fire-fighting room through an air outlet branch pipe at the top end of the reaction room so as to extinguish fire of the fire-fighting room; and in addition, when the fire happened, a first electromagnetic valve is at an off state, and an air sucking pump runs at the same time so as to pump the gas in the fire-fighting room, so that an anaerobic condition of the fire-fighting room is accelerated.