A liquid applying apparatus for fiber products, characterized in that: a first liquid applying device including a first liquid application roller that is operable to coat a first liquid on a first surface of a first fiber product; a second liquid applying device including a second liquid application roller that is adjacent to the first liquid application roller, wherein the first fiber product is movable to pass between the first liquid application roller and the second liquid application roller, and the second liquid application roller is operable to coat a second liquid on a second surface of the first fiber product; and a third liquid applying device including a third liquid application roller that is adjacent to the second liquid application roller, the third liquid application roller being operable to coat a third liquid on a first surface of a second fiber product; wherein the first fiber product and the second fiber product pass between the second liquid application roller and the third liquid application roller and are pressed and laminated by the second liquid application roller and the third liquid application roller; and wherein the first fiber product is a multi-layer fiber product and the second fiber product is a single-layer fiber product, characterized in that the first liquid applying device comprises a first liquid tank and a first liquid pick-up roller, the first liquid pick-up roller being located between the first liquid application roller and the first liquid tank; the second liquid applying device comprises a second liquid tank and a second liquid pick-up roller, the second liquid pick-up roller being located between the second liquid application roller and the second liquid tank; and the third liquid applying device comprises a third liquid tank and a third liquid pick-up roller, the third liquid pick-up roller being located between the third liquid application roller and the third liquid tank. a first liquid applying device including a first liquid application roller that is operable to coat a first liquid on a first surface of a first fiber product; a second liquid applying device including a second liquid application roller that is adjacent to the first liquid application roller, wherein the first fiber product is movable to pass between the first liquid application roller and the second liquid application roller, and the second liquid application roller is operable to coat a second liquid on a second surface of the first fiber product; and a third liquid applying device including a third liquid application roller that is adjacent to the second liquid application roller, the third liquid application roller being operable to coat a third liquid on a first surface of a second fiber product; wherein the first fiber product and the second fiber product pass between the second liquid application roller and the third liquid application roller and are pressed and laminated by the second liquid application roller and the third liquid application roller; and wherein the first fiber product is a multi-layer fiber product and the second fiber product is a single-layer fiber product, characterized in that the first liquid applying device comprises a first liquid tank and a first liquid pick-up roller, the first liquid pick-up roller being located between the first liquid application roller and the first liquid tank; the second liquid applying device comprises a second liquid tank and a second liquid pick-up roller, the second liquid pick-up roller being located between the second liquid application roller and the second liquid tank; and the third liquid applying device comprises a third liquid tank and a third liquid pick-up roller, the third liquid pick-up roller being located between the third liquid application roller and the third liquid tank.