The recycling of polyethylene terephthalate (PET) is of significance to the construction of ecological environment, so the recycling technology and relevant equipment has a broad prospect of application. The disadvantage of traditional PET recycling process is analyzed in this paper, the PET precision co-extrusion process is proposed, and the co-extrusion device is designed. Experimental results show that the co-extrusion technology can meet the requirements of large-scale, continuous, precise and high-quality melting and extrusion process of PET recycling.