Objective To determine the radiation dose of sensitive organs under different protective methods in lung CT scanning environment, and to explore the best protective scheme of corresponding organs. Methods Annealed thermoluminescence dose elements were placed in the stomach, liver, colon, and thyroid gland of a simulated human body model. The dose effect experiment of protective methods included non-protective group, half lead apron group, and full lead apron group. The dose effect experiment of protective thickness included 0.50 mmpb full lead apron group and 0.35 mmpb full lead apron group. The same exposure conditions of lung CT scan were used in the above experiments. Results Compared with the non-protective group, the exposure dose of the stomach, liver, colon, and thyroid gland increased significantly in the half lead apron group (P < 0.05), and the exposure dose of the thyroid gland and colon decreased significantly in the full lead apron group (P < 0.05). There were no significant differences in the exposure dose of the liver, stomach, and colon in the simulated human body model between the 0.35 mmpb full lead apron group and the 0.50 mmpb full lead apron group. Conclusion For lung CT scan, the protective measure of lead apron may not reduce the exposure dose of subjects. The protective thickness of lead apron does not necessarily have a substantial influence on the exposure dose of human body.