The utility model discloses a cementing packer, this packer includes: top connection, lower clutch, the center tube, the one end of center tube is with the top connection is continuous, the other end is continuous with the lower clutch, first deblocking part and second deblocking part, wherein, work as sit and seal piston pushing the compression of jump ring cover behind the seat packing element, can be through cutting the sliding sleeve deblocking shear pin in the first deblocking part for the cylindric lock was cut to the deblocking sliding sleeve under upward the deblocking sliding sleeve can move down the promotion, and then made a seat packing element make progress the extension in order to accomplish the deblocking, and/or, through cutting the packing element deblocking shear pin in the second deblocking part for sit and seal packing element extension downwards in order to accomplish the deblocking. At above -mentioned technical scheme, through set up two deblocking parts on the packer for the packer wait to congeal the back at cement, sits to seal a packing element and can extend the deblocking through the orientation to the difference, thereby solves among the prior art the not technical problem of deblocking thoroughly or not of packer deblocking.