Two-wall hollow fabricated root-type open caisson foundation

The invention discloses a two-wall hollow fabricated root-type open caisson foundation. The two-wall hollow fabricated root-type open caisson foundation is composed of a shaft, root keys and a back cover, the shaft is of an annular tubular structure with two hollow walls, and is composed of a shaft inner wall, a rib wall and an outer wall in the radial direction, and a formed cavity between the well walls communicates vertically so that mud sucking equipment can be lowered and moved in the cavity between the well walls; bottom feet of the shaft are blade feet, and root keys are arranged on thepositions, penetrating through the shaft inner wall, the rib wall and the outer wall and protruding and extending from the outer wall, of the shaft; the shaft is formed by connection of a bottom segment and a plurality of standard segments in the vertical direction, the bottom segment is in a blade shape, and the blade feet are formed; and for the shaft which is completely jointed and sunk in place, the root keys are arr