The utility model relates to a limekiln top seal device, especially a kiln gas seal structure is used at limekiln top. It is including setting up at the seal assembly between rotatory hopper and the commentaries on classics bucket cover, setting up at feeding elephant trunk end opening and turn over the 2nd seal assembly between the board and set up the 3rd seal assembly who is changeing between bucket cover and the material legendary venomous insect jib, and a seal assembly, the 2nd seal assembly and the 3rd seal assembly are the dynamic seal structure. The beneficial effect of the utility model: have characteristics high temperature resistant, corrosion -resistant, the ageing resistance, alleviate the impact damage to the rigidity valve plate, sealed leakage problem and the bite problem of rigidity has effectively been solved, the difficult rail wheel cluster axle that takes place has ensured that the operation of rotatory hopper is stable, simple structure, the design is compact, uses the effect showing, need not to drop into great number expense, long service life to recovering maintenance work after the equipment that has significantly reduced damages.