The invention discloses a mesh-belt furnace oily smoke filtering device. According to the technical scheme, the mesh-belt furnace oily smoke filtering device comprises a filtering pipe arranged insidea smoke vent of a mesh-belt furnace, the inside of the filtering pipe is provided with a first mesh plate, and the upper surface of the first mesh plate is covered by a plurality of filter sands; a collecting device for collecting dropped condensed oil dirt is arranged under the first mesh plate; the collecting device comprises a first guide plate fixed onto the inner wall of the filtering pipe and inclined downwards, and a second guide plate fixed onto the inner wall of the filtering pipe and parallel to the first guide plate; the lower portion of the first guide plate is provided with a first notch, the second guide plate is arranged under the first guide plate, the upper portion of the second guide plate is provided with a second notch, and the first notch and the second notch are arranged in a staggered mode; the oil dirt is retained at the included-angle portion between the second guide plate and the filtering pipe, and the side wall of the filtering pipe is provide with a discharging port for discharging the oil dirt. The mesh-belt furnace oily smoke filtering device can conveniently collect the oil dirt of exhaust of the mesh-belt furnace and reduce environmental pollution.