The utility model relates to a be applied to the colliery and combine support stand jack sealed dust cover, the especially pull out support stand jack dust cover specialized tool of the equipment of adopting. Specialized tool include semicircle main part, first articulated slab, second articulated slab, double-screw bolt, nut, concentric and both ends swing joint two semicircle main parts that the radius size is the same become integrative, wherein upper and lower place at a first articulated slab of serving of two semicircle main parts articulated positions articulated fixed with the one end of two semicircle main parts articulated positions, the other end of two articulated positions of semicircle main parts with place at the other end of the two semicircle main parts articulated positions second articulated slab swing joint on simultaneously, seted up the screw in the semicircle main part, the screw is about the line symmetric distribution of the articulated position of two semicircle main parts of integral type. The utility model has the advantages of being simple in structure and convenient in operation, simplified and pulled out dust cover technology, saved the time, improved and changed the sealed efficiency of support stand jack.