The invention discloses a device and method for manufacturing carrier bands. The upper and lower surface of each recessed part of a carrier band, which is manufactured by the device and the method provided by the invention, are directly attached between the upper mould seat and the lower mould seat of a processing mould, thus each upper surface and the lower surface are all in a flat state, the angle and the size of the carrier band are more precise, the bag thickness is uniform, furthermore, an excellent sealing force between the carrier band and the adhesive tape coated on the carrier band is obtained, so the adhesive tape is not easy to fall off, and the electronic component is not easy to fall out. At the same time, the side surfaces of the projecting part and recessed part of the upper mould seat and the lower mould seat of the device which processes the carrier band, are inclined planes, so the carrier bands, which have been processed and molded, can easily fall off from the inclined planes of the device, and thus the phenomenon that carrier bands are adhered on the upper mould seat or the lower mould seat, and then are tore or destroyed is avoided.