Peripherally inserted central venous catheter PICC is very important for parenteral nutrition and chemotherapy in patients with carcinoma. In July 2021 Chinese Society of Nutritional Oncology released the Guidelines for Nutritional Therapy Pathways for Adult Patients in China. To provide patients with safe and effective PICC this guideline is formulated in accordance with the principles of evidence-based medicine and based on the best current evidence. The guidelines are written concisely and easily for clinicians and nurses to use in clinical practice. The guidelines give the level of evidence based on the GRADE and 8 recommendations on how to choose the puncture site how to guide the puncture how to maintain patency and how to treat after blockage. According to the guideline it would promote early recovery of patients and reduce catheter-related infection complications. This article mainly introduces and interprets the main contents of this guideline from the aspects of guideline overview PICC technology indications complications recommendations and evidence evaluation to provide the latest evidence-based medical evidence for the application of PICC during nutritional therapy in Chinese adult patients.