A casting-formed waterproof chassis for a whole bathroom comprises a chassis body. The chassis body comprises an aluminum section frame (1) and an aluminum core honeycomb (2), the aluminum section frame (1) being a hollow closed frame, the aluminum section frame (1) enclosing the aluminum core honeycomb (2), and a gap being reserved between the aluminum core honeycomb (2) and the aluminum section frame (1); a continuous and closed groove (4) is formed in the gap, and the groove (4) is internally filled with fiber reinforced plastic resin; the fiber reinforced plastic resin is also poured onto the upper surface and the lower surface of the aluminum core honeycomb (2); a fiber reinforced plastic resin casting molding process is used for integral forming of the fiber reinforced plastic resin, with which the groove (4) is internally filled, and the fiber reinforced plastic resin poured onto the upper surface and the lower surface of the aluminum core honeycomb (2), and a hollow and totally-enclosed capsular fiber reinforced plastic resin sleeve (5) is formed; and the fiber reinforced plastic resin sleeve (5) is separately and closely connected to the aluminum section frame (1) and the aluminum core honeycomb (2). A mould does not need to be made in advance for the waterproof chassis, and the waterproof chassis is good in waterproofness, light in mass and long in service life.