An interlayer mixing apparatus for texturing man-made stone slabs, comprising a pressing assembly, a pigment applying assembly, a stirring assembly, a moving assembly, and a control system. A slab is conveyed to working areas of the pressing assembly, the pigment applying assembly, and the stirring assembly by means of a conveyor belt in sequence. The pressing assembly, the pigment applying assembly, the moving assembly, and the stirring assembly are separately connected to the control system. The control system adjusts the moving assembly and the stirring assembly, so that the moving assembly drives the stirring assembly to move above the stone slab to which extrusion force is applied and according to a set route of a texture on a final product; meanwhile, the stirring assembly performs stirring at all corresponding positions or local corresponding positions on the surface of the slab, wherein the stirring occurs between a pigment and a raw material mixture of the slab. Before stirring, the pigment and the slab are first pressed by means of the pressing assembly, so that the boundary of the texture on the final product is clearer and more complete in macroscopic view.