The invention relates to a high-temperature pressure sensor back-end packaging structure and a packaging method, which solves the problem that the high-temperature pressure sensor cannot work normallydue to heating failure in a high-temperature environment due to unreasonable structure under a harsh service environment. The invention comprises a cylindrical shell with a sandwich, the sandwich isfilled with a heat radiation protection material, one end of the cylindrical housing is provided with a threaded connector, The other end of the cylindrical housing is provided with a cable fixing head and a fastening nipple; a nano-porous gas gel with a conductor through hole is arranged in a cylindrical shell and the cable fixing head, the fastening nipple is encapsulated with a conductor connector extending into the conductor through hole, and the tungsten pin and the conductor bonding joint are encapsulated in the interconnecting head. The invention has the advantages of reasonable structure, good heat dissipation performance of the shell and tube, stable and reliable operation of the internal circuit protection, and meets the requirement of pressure measurement of the pressure sensorunder the high temperature environment.