Peripherally inserted central catheter (PICC), as one of the important intravenous routes for the rescue and treatment of critically ill patients, has been widely used in the fluid resuscitation of critically ill patients in intensive care. In particular, PICC can be widely used in the treatment of cancer patients. With the wide application of peripheral central venous catheterization, the clinical findings of bloodstream infection complications caused by PICC have gradually attracted the attention of doctors and patients.To investigate the effect of specialized placement and PICC placement care on patients with lung cancer who underwent PICC puncture. Patients were selected and divided into a comparison group and an observation group of 40 patients each according to the randomized residual grouping method. In the comparison group, routine PICC placement and catheter maintenance were performed, while the observation group was provided with specialized placement and PICC placement care. The differences in immune and tumor marker levels and nursing compliance between the two groups were observed and compared before and after nursing care.There was no significant difference in the comparison of tumor marker levels between the two groups of patients before care, while the levels of CYFRA21-1, CA125, and VGEF in the observation group were significantly lower than those in the comparison group after care, and this difference was statistically significant (P < 0.05). There was no statistically significant difference in the comparison of immune levels between the two groups before care (P > 0.05), while the comparison of CD4+, CD3+, and CD4+/CD8+ after care was significantly different and higher in the observation group than in the comparison group, and the comparison was statistically significant (P < 0.05). The compliance rate of 93.8% in the observation group was significantly higher than that of 77.9% in the comparison group, and this difference was statistically significant for comparison (P < 0.05).PICC placement care is more effective in patients with lung cancer and performing PICC puncture, significantly improves patients' immune and tumor marker levels, improves patients' negative emotions, reduces disease uncertainty, and improves nursing compliance.Copyright © 2022 Qiu Hu et al.