A shaft sealing assembly, comprising a first sealing assembly which uses a liquid membrane formed by fluid static pressure to seal a reactor coolant pump under normal operation condition, wherein the shaft sealing assembly further comprises a passive stopping sealing member disposed in the first sealing assembly and used to seal the reactor coolant pump under a station blackout condition, the passive stopping sealing member comprises an induction driving portion and a sealing ring provided in a circumferential direction of a pump shaft of the reactor coolant pump, the sealing ring has an opening, the induction driving portion is used to, after sensing high-temperature fluid flowing into the first sealing assembly upon the station blackout condition, drive the sealing ring to close and holds the pump shaft of the reactor coolant pump tightly, a gap between the first sealing assembly and the pump shaft of the reactor coolant pump is blocked, and the reactor coolant is prevented from leaking along the pump shaft, wherein the induction driving portion comprises a fusible support ring and an elastic pressing ring, the fusible support ring is made from a fusible material which fusing point is lower than the temperature of the high-temperature fluid; under normal operation condition, the fusible support ring is used to prevent the elastic pressing ring from applying a radial pressure to the sealing ring; under the station blackout condition, the fusible support ring is fused by the high-temperature fluid, and the elastic pressing ring applies a radial pressure to the sealing ring to close the sealing ring, wherein the first sealing assembly comprises a first sealing member, a first sealing insert and a first sealing insert support disposed in turn between a water power member and a motor; the passive stopping sealing member is disposed in the first sealing insert adjacent to one end of the first sealing insert support or in the first sealing insert support adjacent to one end of the first sealing insert, wherein the induction driving portion further comprises a piston driving ring disposed around the sealing ring, the elastic pressing ring is disposed on one side of the piston driving ring away from the fusible support ring; a first slope is on one side of the sealing ring toward the piston driving ring; on one side of the piston driving ring toward the sealing ring there is a second slope tangential with the first slope, and a diameter of the piston driving ring gradually reduces in a direction from the elastic pressing ring towards the fusible support ring; under normal operation condition, one end of the fusible support ring abuts against the first sealing insert support or the first sealing insert, and the other end abuts against the piston driving ring; under the station blackout operation condition, the fusible support ring is fused by the high-temperature fluid, and the piston driving ring, under action of the pressing force of the elastic pressing ring, pushes the sealing ring upwardly to retract inwardly so that the sealing ring holds the pump shaft tightly and achieve the sealing function, characterized in that the passive stopping sealing member further comprises a fusible limiting ring configured to limit movement of the sealing ring away from the piston driving ring under normal operation condition, and the fusible limiting ring is made from a fusible material which fusing point is lower than the temperature of the high-temperature fluid.