The sealing assembly for the observation operation hole on the top plate of the baking furnace developed by our company overcomes the shortcomings of existing technology, where the thermal insulation cover for the observation operation hole requires considerable labor intensity, long operation time, and results in significant heat loss during opening and closing. The sealing covers produced by us for the observation operation hole feature high flexural strength at elevated temperatures, excellent thermal shock stability, and high refractoriness under load, along with other outstanding physical and chemical performance indicators.