Objective To investigate the radiation protective methods in MSCT for children tracheobronchial foreign body. Methods Totally 80 children with tracheobronchial foreign body were randomly divided into control and experimental groups. The patients of control group were performed by standard-dose CT scan (120?kV, 80?mA, range: from throat to diaphragm), and the low-dose MSCT scan (100?kV, 30?mA, range: from epiglottis to diaphragm, removing the head holder) was used in experimental group. CT performances were compared with the bronchoscopy. Results The computed tomography dose index (CTDI) and the dose-length product (DLP) of experimental group were significantly lower than that of control group, and the radiation dose was 60% of the control group. The image quality of the two groups was excellent. Compared with the bronchoscopy, the diagnostic accuracy of the experimental group was 100%, and it was 95% for the control group. Conclusions By using low dose MSCT, with head holder removal and scan range from epiglottis to diaphragm can improve the accuracy of diagnosing children tracheobronchial foreign body and reduce radiation dose.