The utility model relates to a big flood mine chamber waterproof construction belongs to secret mine engineering construction equipment technical field. Technical scheme is: contain metal mesh (1), shotcrete (2), seepage -proof concrete (3), stock (4), waterproof board (5) and chamber (6), stock (4) anchor is on the wall of chamber (6), metal mesh (1) is fixed on the wall of chamber (6) through stock (4), spray on metal mesh (1) on chamber (6) wall shotcrete (2), waterproof board (5) are fixed at shotcrete (2) on the surface, the outside pouring seepage -proof concrete (3) of waterproof board (5). The beneficial effects of the utility model are that: can use in big flood mine chamber support, effectively solve the chamber because of gushing water unable problem of checking and accepting not up to standard, compare the mode of carrying out measures such as grouting behind shaft and drift lining again after the strutting in the past, save cost and time limit for a project more.