Bottom wall body and waterproof building wall

The utility model provides a bottom wall body and a waterproof building wall, and relates to the field of buildings. The bottom wall is applied to the two sides of the bottom of a window frame and comprises an indoor wall body, an outdoor wall body and a wall foundation, and the indoor wall body and the outdoor wall body are built on the two sides of the wall foundation with the window frame as the boundary. A flame-retardant plate is laid on the indoor wall body in the shape of a wall foundation, a PVC groove plate is laid in the vertical direction of the flame-retardant plate, and a stainless steel plate is arranged in the horizontal direction of the flame-retardant plate. A cement mortar layer is outwards arranged on the outdoor wall body along the shape of the wall foundation, and an artificial stone plate is arranged outside the top side of the cement mortar layer. Different waterproof and moisture-proof materials are arranged on the two sides of the wall body according to different environments, so that