A waste gas treatment device for small- and medium-sized industrial furnaces comprises a waste gas treatment tank, a sedimentation tank, a reduction tank, an air stripping tank and a clear water tank.The waste gas treatment tank comprises a washing and dedusting area, a fluidization area, a biological adsorption area, a demister, an activated carbon area and an exhaust fan sequentially from bottom to top. A waste gas washing component is arranged in the washing and dedusting area and comprises tap water sprayers, a conical waste water collecting tank, a gas inlet pipe and a gas distribution pipe. Fluidization liquid sprayers, fluidization filler, a fluidization liquid storage tank and a storage tank fluidization liquid discharging pipe are arranged in the fluidization area. The demister is a baffle plate demister or a cyclone plate demister, the reduction tank comprises a mixing area and a settling area, the air stripping tank comprises an air stripping area and a separation area, andthe clear water tank is provided with a clear water tank water inlet pipe and a clear water tank water outlet pipe.