Abstract: The central pumping station in 21 mining area is an important dewater chamber of the mining area, chamber widths more than 6 m are typical large span and high sectional requirements underground chamber. Taking 21 mining area central pumping stations as the study object, survey analysis, numerical simulation, field trials and field measurement method are used to focus on the dynamic pressure induced floor large span the chamber support technology, and deeply analyze the dynamic pressure patterns, and put forward support technology of floor large-span chamber effected by dynamic pressure.