Abstract: [Objective] To compare and analyze the accuracy of preoperative measurement of DR and contralateral shank length in predicting the length of tibial intramedullary nails and whether the combination of the two methods has advantages. [Method] 67 patients with tibial shaft fracture who were treated with tibial intramedullary nail from June 2016 to December 2018 were divided into two groups A and B. Group A (contralateral shank measurement): 32 patients were treated with intramedullary nail retrospectively. Previously, the length of contralateral shank was purely measured in our hospital preoperatively to guide the selection of intramedullary nail length during operation. Group B (image measurement combined with contralateral shank measurement): 35 patients were prospectively collected for intramedullary nail therapy. The length of intramedullary nail was predicted by image measurement combined with contralateral shank measurement. The two measurements were averaged and predicted the length of nails during operation. By collecting the length of the intramedullary nail, the operation time, the amount of bleeding, and the times of replacing nails, the absolute difference between the data of the two groups and the length of the nails used in the operation was evaluated. [Results] Compared with the two groups, the absolute value of the difference between preoperative predictive value of intramedullary nail and intraoperative length of nail in group B was (4.35±2.96) mm less than that of group A (11.25±7.96) mm (P<0.05). There was no significant difference in operation time and the times of nail replacements between the two groups (P>0.05)，but there was significant difference in the amount of bleeding between the two groups (P < 0.05), and there was no significant difference between the two methods in group B (P>0.05). [Conclusion] The preoperative DR measurement combined with the measurement of contralateral shank is more accurate than the method of single measurement of the contralateral leg length. However, there was no significant difference between the two methods in predicting the length of intramedullary nails.