A folding slab and central column composite joint, comprising a steel-wood composite column, square wood beams, connecting assemblies for connecting the steel-wood composite column and the square wood beams, and folding wood slabs connected with and supported by the steel-wood composite column, the square wood beams and the connecting assemblies, wherein: the steel-wood composite column comprises a hollow cross-shaped outer wood column, wherein a steel sleeve is inlaid in the cross-shaped outer wood column, an inner wood column is inlaid in the steel sleeve, column vertical steel bars penetrate through the inner wood column, inner ends of horizontal steel bars penetrate through the cross-shaped outer wood column to be fixedly connected to the steel sleeve, tapered threads are arranged at outer ends of the horizontal steel bars, and first bolt holes to be connected to the connecting assemblies are formed in two sides of a cross-shaped surface of the cross-shaped outer wood column; the square wood beams have vertical protruding steel bars stretching therein, and threads are arranged at outer ends of the vertical protruding steel bars; second bolt holes to be connected to the double ring plates are formed in two sides of ends of the square wood beams, and third bolt holes to be fixedly connected to the folding wood slabs are formed in tops of the square wood beams; and a spindle is connected between every two adjacent said folding wood slabs, and third bolt holes to be connected to the square wood beams and the connecting assemblies are formed in edge joints of the folding wood slabs; each said connecting assembly comprises a threaded sleeve having two ends respectively connected to the horizontal steel bars and vertical protruding steel bars, and a double ring plate; the double ring plate comprises a cross-shaped upper ring plate and a cross-shaped lower ring plate, wherein corner plates are arranged on connected cross-shaped roots of the upper ring plate and the lower ring plate, and fourth bolt holes used for fixed connection after the upper ring plate and the lower ring plate are overlapped are formed in the corner plates; first bolt holes to be connected to the cross-shaped outer wood column are formed in inner ends, close to the cross-shaped roots, of the upper ring plate and the lower ring plate; second bolt holes to be connected to the square wood beams are formed in outer sides of ends of the upper ring plate and the lower ring plate; and third bolt holes to be connected to the square wood beams and the folding wood slabs are formed in top ends of the upper ring plate and the lower ring plate. the steel-wood composite column comprises a hollow cross-shaped outer wood column, wherein a steel sleeve is inlaid in the cross-shaped outer wood column, an inner wood column is inlaid in the steel sleeve, column vertical steel bars penetrate through the inner wood column, inner ends of horizontal steel bars penetrate through the cross-shaped outer wood column to be fixedly connected to the steel sleeve, tapered threads are arranged at outer ends of the horizontal steel bars, and first bolt holes to be connected to the connecting assemblies are formed in two sides of a cross-shaped surface of the cross-shaped outer wood column; the square wood beams have vertical protruding steel bars stretching therein, and threads are arranged at outer ends of the vertical protruding steel bars; second bolt holes to be connected to the double ring plates are formed in two sides of ends of the square wood beams, and third bolt holes to be fixedly connected to the folding wood slabs are formed in tops of the square wood beams; and a spindle is connected between every two adjacent said folding wood slabs, and third bolt holes to be connected to the square wood beams and the connecting assemblies are formed in edge joints of the folding wood slabs; each said connecting assembly comprises a threaded sleeve having two ends respectively connected to the horizontal steel bars and vertical protruding steel bars, and a double ring plate; the double ring plate comprises a cross-shaped upper ring plate and a cross-shaped lower ring plate, wherein corner plates are arranged on connected cross-shaped roots of the upper ring plate and the lower ring plate, and fourth bolt holes used for fixed connection after the upper ring plate and the lower ring plate are overlapped are formed in the corner plates; first bolt holes to be connected to the cross-shaped outer wood column are formed in inner ends, close to the cross-shaped roots, of the upper ring plate and the lower ring plate; second bolt holes to be connected to the square wood beams are formed in outer sides of ends of the upper ring plate and the lower ring plate; and third bolt holes to be connected to the square wood beams and the folding wood slabs are formed in top ends of the upper ring plate and the lower ring plate.