Fully-sealed grid bottom door device and railroad hopper car

The invention discloses a fully-sealed grid bottom door device and a railway hopper car. The bottom door device comprises bottom door frame units, a grid door unit, a first flexible sealing unit, a second flexible sealing unit and a driving unit. The two bottom door frame units are oppositely arranged; the bottom door frame unit comprises a longitudinal supporting part and a transverse connecting part, and a groove is formed in the longitudinal supporting part; the two grid door units are oppositely arranged; the grid door unit comprises a grid plate; the two ends of the grid plate are inserted into the grooves and can slide in the grooves; when the bottom door device is closed, the transverse connecting parts can completely cover gaps formed between the adjacent grid plates; when the grid plates are opened, the transverse connecting parts are located over the grid plates, and a leakage bin structure can be formed between every two adjacent grid plates. The driving unit is arranged between the two grid door u