Objective: To explore the effect of intensive nursing on the incidence of thrombosis in patients undergoing PICC line placement. Methods: A total of 50 patients with tumor who underwent PICC line placement in Jiangsu Zhenjiang First People’s Hospital (from January 2019 to January 2020) were randomly selected for this research. According to the random number table method, they were divided into two groups: group A (25 cases) for routine nursing and group B (25 cases) for intensive nursing. The incidence of thrombosis, coagulation indices, quality of life, and nursing satisfaction were compared between the two groups. Results: The incidence of thrombosis of group B was lower than that of group A, and the coagulation indices, quality of life, as well as the nursing satisfaction of group B were higher than those of group A (P < 0.05). Conclusion: Intensive nursing can effectively improve the coagulation, reduce thrombosis, and improve the quality of life of patients. The clinical application effect is remarkable, and it should be popularized.