Smoke blocking system for large-span space

The invention discloses a smoke blocking system for a large-span space. The smoke blocking system comprises a fixed smoke blocking structure and a movable smoke blocking structure. The movable smoke blocking structure comprises a plurality of electric reels which are located between a floor and a suspended ceiling and arranged in an end-to-end overlapping mode in the horizontal linear direction, sliding rods are arranged in the electric reels in a penetrating mode, the sliding rods extend out of the two ends corresponding to the electric reels and form two extending sections, and the bottoms of the two extending sections are symmetrically and obliquely connected with blocking rods; a plurality of pieces of fireproof cloth are correspondingly wound on the plurality of electric reels, an opening for the fireproof cloth to penetrate out is formed in the suspended ceiling, and the two sides of the fireproof cloth cover the two extension sections and are guided to the opening through the two stop levers; the incli