Abstract: Objective: To investigate the role of single nostril deep breathing combined with anterior catheter drift in the prevention of primary ectopic of PICC catheterizationMethods: A total of 166 breast cancer patients who underwent PICC operation in our hospital from January 20 to December 1818 were selected. The patients were divided into the control group and the experimental group. The former was performed PICC operation with the head-turning method in 85 cases. Eighty-one patients underwent catheterization with a single nostril deep-breathing combined with anterior catheter drift method. The ectopic status of the two groups, the time required for catheterization, and the satisfaction of care were compared. Results: The incidence of primary ectopic in the experimental group was 3.70%, which was significantly lower than that in the control group (15.29%)，P <0.05 in all of the above.Conclusion: The single nostril deep breathing combined with the anterior catheter drift can prevent the occurrence of PICC ectopic, improve the success rate of catheterization.It is worthy of popularization in clinical practice