Large-span combined construction platform

The utility model relates to a large-span combined type construction platform. A center column of an existing silo work platform is large in diameter, construction wastes time and money, and therefore the large-span combined type construction platform comprises the center column, a plurality of bailey beams and a disc piece capable of being welded at the top of the column, the disc piece capable of being welded at the top of the column comprises a top circular ring disc, a center cylinder and a bottom circular ring disc which are welded in sequence, and the center column comprises three branch columns. Each sub-column is formed by sequentially connecting a weldable top column and a plurality of standard columns from top to bottom through flange plates and bolts, and the weldable top columns of the three sub-columns are welded to the lower surface of the bottom circular ring disc of the column top weldable disc piece; each bailey beam comprises a weldable non-standard frame, a plurality of standard frames and