Steel-structure string truss system roof ceiling structure and construction method thereof

The invention provides a steel-structure string truss system roof ceiling structure. The steel-structure string truss system roof ceiling structure comprises a string truss system, a roof and a ceiling frame. Particularly, the ceiling frame is mounted on the lower portions of upper string beams of the string truss system through a plurality of hanging columns; the top ends of the multiple hanging columns are vertically connected to the two sides of the upper string beams of the string truss system through hanging column connecting pieces; ceiling connecting pieces are arranged at the lower ends of the hanging columns; the ceiling frame comprises a plurality of ceiling truss units; and the edges of the ceiling truss units are connected with the ceiling connecting pieces of the hanging columns. The roof ceiling structure has the characteristics of being simple in structure, firm and easy to construct. The invention further provides a construction method of the roof ceiling structure. The construction method com