The invention provides a packer and a use method thereof. The packer comprises a center tube and a first seat seal mechanism, a second seat seal mechanism and an anchoring mechanism which are arranged on the outer side of the center tube in sequence in a sleeving mode; the first seat seal mechanism comprises a rubber cylinder and an extrusion part, the lower end of the rubber cylinder is fixed to a first cone through a rubber cylinder support, and the upper end of rubber cylinder can slide on the outer wall of the center tube in a limiting mode through the extrusion part; the second seat seal mechanism is provided with a slip and the first cone, and the first cone can be fixedly inserted into the slip in a matched mode; the anchoring mechanism comprises a stable part and a clamping part, the stable part comprises a centralizer, and a centralizer base is connected with the slip base. The packer and the use method thereof are suitable for a composite seat seal packer of a highly-deviated well, and the requirement of oil extraction production is met.