The invention discloses a gas-
solid dust sealing device. The gas-
solid dust sealing device comprises a building platform, an ash 
silo, a penetrating opening and a steel 
wire rope, wherein the ash 
silo is arranged above the building platform, the penetrating opening is formed in the side wall of the ash 
silo, and the gas-
solid dust sealing device further comprises a 
positive pressure tank, a tightening force tank and a negative pressure tank which sequentially communicate with one another in the radial direction, and the penetrating opening is detachably connected with the 
positive pressure tank; one end of the steel 
wire rope sequentially penetrates through the negative pressure tank, the tightening force tank, the 
positive pressure tank and the penetrating opening and then extends into the ash silo; a sealing 
pipe is arranged in the positive pressure tank, a plurality of sealing holes are formed in the sealing 
pipe, and a pipeline I is arranged on the positive pressure tank to communicate with a positive pressure air source; an upper pressing ring and a lower pressing ring are elastically connected into the tightening tank, the space between the upper pressing ring and the lower pressing ring is filled with rock 
wool, and the steel 
wire rope is tightly wrapped with the rock 
wool; and a pipeline II is arranged on the negative pressure tank to communicate with a negative pressure air source. Through a three-stage sealing structure, it is effectively guaranteed that dust does not overflow, it is guaranteed that dry ash filling operation meets the 
environmental protection requirement, the actual production requirement of an enterprise is met, and good practicability is achieved.