Novel nuclear main pump static pressure shaft seal structure capable of remarkably improving stability

The invention relates to a novel nuclear main pump static pressure shaft seal structure capable of remarkably improving stability, which comprises a rotary sealing assembly and a fixed sealing assembly, the rotary sealing assembly and the fixed sealing assembly each comprise a mounting seat, a sealing ring and a pressing ring, and the sealing ring of the rotary sealing assembly and the sealing ring of the fixed sealing assembly abut against each other. A first sealing piece used for abutting against the sealing ring is annularly arranged on the mounting base, the pressing ring is used for abutting against the sealing ring and the mounting base at the same time, and a mounting piece used for fixing the pressing ring to the mounting base so as to drive the sealing ring to abut against the first sealing piece is arranged on the pressing ring. When the installation piece fixes the pressing ring to abut against the installation base, a balance pressure gap is reserved between the sealing ring and the installation