The present invention provides a manufacturing method of three-dimensional
cross-linked foam for uppers of shoes, comprising: preparing a plurality
of foaming materials in a planar or three-dimensional shape with a
cross-linked foaming suppressed; forming at least one interfacing pattern
on at least one foaming material to prevent physical and chemical
interactions between the foaming materials, the interfacing pattern
formed of at least one interfacing material; cross-linked foaming of the
foaming material having the interfacing pattern thereon to obtain a
cross-linked foam in a planar shape, the cross-linked foam having at
least one inner cavity structure therein; and vacuum molding the planar
cross-linked foam in a vacuum molding die to obtain a cross-linked foam
having a shape corresponding to a last, the planar cross-linked foam
disposed in a cavity of the vacuum molding die, the cavity having a shape
corresponding to the last.