The invention relates to a tunnel type peripherally inserted central catheter and an auxiliary device thereof, and belongs to the fields of a medical apparatus and a biocompatible material. The product mainly consists of a tunnel needle and a peripherally inserted central catheter, wherein the tunnel needle is subjected to roughening treatment and is clear in development under ultrasonics; the catheter is divided into a near end, a far end and a tip end which are different in material hardness, and the material hardness of the near end is greater than that of the far end and greater than thatof the tip end; the surface of the near end of the catheter is coated with a bacterium resisting coating, and the surface of the far end of the catheter is coated with an anticoagulation coating; a tunnel type method is adopted for duct placing, a subcutaneous tunnel is built, and a certain distance is formed between the puncture point of blood vessels and the outlet of the duct. The tunnel is arranged, so that the position of the outlet of the catheter is away from the puncturing position, the thrombosis incidence can be reduced, and the application range of PICC is increased. The tunnel forms a pollution preventing barrier, so that infection caused by external factors can be effectively avoided. The subcutaneous tunnel can also well fix the catheter, so that the catheter displacement rate can be reduced.