Objective To investigate the incidence and factors influencing blockage of double-lumen power injectable PICCs in children undergoing hematopoietic stem cell transplantation (HSCT), and to provide references for improving catheter care. Methods Clinical data of 296 children with double-lumen Power PICC were retrospectively collected. The influencing factors of catheter blockage were identified by univariate analysis and multivariate logistic regression. Results The incidence of catheter blockage in this sample was 26.69%. Age, whether intravenous use of cyclosporine A, whether having catheter dislodgement, or whether catheter with valve were factors influencing catheter blockage in children undergoing HSCT (all P<0.05). Conclusion The incidence of blockage of double-lumen Power PICCs in children undergoing HSCT is relatively high. Special attention should be paid to children who are relatively young and who receive intravenous cyclosporine A. Meanwhile, catheter dislodgement should be avoided. If conditions permit, we recommend using double-lumen Power PICC with valve to prevent catheter blockage.