Cast-in-place beam built-up plate system and construction method thereof

The invention relates to a cast-in-place beam built-up plate system and a construction method of the plate system. A side built-up plate in the plate system consists of a web panel made of bamboo plywood, a flange plate panel made of bamboo plywood, a web skeleton nailed on the back side of the web panel, and a flange plate skeleton nailed on the back side of the flange plate panel; the flange plate skeleton consists of a row of longitudinal flange plate keels, a row of arc-shaped flange plate keels, and a row of longitudinal flange plate back ridges; the row of longitudinal flange plate keels are nailed on the back side of the flange plate panel and manufactured by square timber, the row of arc-shaped flange plate keels are connected at the outer sides of the row of longitudinal flange plate keels and arranged along the longitudinal direction at intervals, and the row of longitudinal flange plate back ridges are connected at the outer sides of the row of arc-shaped flange plate keels and manufactured by steel pipes; and each arc-shaped flange plate keel consists of two bent shaped steel pipes which are connected together in a welding manner, and a pair of shaped steel pipe connecting ribs which are symmetrically connected at two sides of the two shaped steel pipes in a welding manner. The built-up plate system is low in manufacturing cost, simple and convenient to assemble and disassemble, and reusable; and the construction method is simple and feasible and economical and practical.