Expansion sealing element of fireproof door

The utility model provides a fireproof door expansion sealing piece, a first connecting column is fixedly arranged in the middle of the left side of a first edge covering sleeve, and a first clamping block is fixedly arranged on the left side of the first connecting column. According to the expansion sealing piece of the fireproof door, the first edge covering sleeve, the second edge covering sleeve, the first clamping block and the second clamping block are matched with one another, and the first clamping block and the second clamping block are inserted into clamping grooves of the fireproof door respectively, so that the expansion sealing piece is connected in a door slot; the connection stability is improved through first anti-skid convex teeth and second anti-skid convex teeth, slippage is avoided, the width of the expansion sealing piece can be increased through a fireproof expansion bag assembly and a telescopic spring, the expansion sealing piece can adapt to gaps with different widths, and the expansi