The application discloses a hollowed-out printed object and a 3D printing support, a 3D printing support construction method and a 3D printing method of the hollowed-out printed object. At least one end of the 3D printing support of the hollowed-out printed object is connected to the hollowed-out printed object; the support includes a main body and a connecting portion connected to the hollowed-out printed object; a joint between at least part of the connecting portion and the hollowed-out printed object is located inside the hollowed-out printed object.