Automatic filling and sealing device for coal seam dynamic cracks and method

The invention discloses an automatic filling and sealing device for coal seam dynamic cracks and a method. The automatic filling and sealing device comprises a conventional sealing system and a dynamic sealing system. The conventional sealing system mainly adopts the hole sealing technology of pressurized 'two-plugging and one-injecting' with the hole sealing depth being 5-12m to conduct one-time sealing on an extraction drill hole; and the dynamic sealing system mainly adopts a plurality of dynamic sealing holes around the extraction drill hole to conduct multiple times of dynamic sealing. A gas density detector connected with an opening of a gas extracting pipe in the conventional sealing system is used for detecting gas density in real time; a slurry pressure detector is connected with an opening of a dynamic sealing drill hole slurry injecting pipe in the dynamic sealing system to detect slurry pressure in the slurry injecting pipe; and the microprocessors analyze the data transmitted from the detectors t