Abstract: Objective To quantitatively evaluate the sealing efficiency of the most common root canal treatment methods so as to provide a theoretical basis for clinical targeted selection of root canal treatment methods by cone- beam compute tomography. Methods Forty-five extracted single root anterior teeth and premolars were randomly divided into three groups, 15 in each. The first group was instrumented with NiTi K-files and filled by lateral compaction.The second group was instrumented with ProTaper NiTi rotary files and filled by lateral compaction.The last group was instrumented with ProTaper NiTi rotary files and filled by continuous warm vertical condensation. The root canal volume after preparation and filling of each canal was measured by cone-beam compute tomography and the percentage of obturated volume (POV) of an overall root canal was calculated. The POV of coronal third, middle third and apical third of root canals could be also obtained. Wilconxon-Mann-Whitney U analysis was performed. Results The first and the second group had no statistically significant difference in the POV of the overall, coronal third, middle third and apical third of the root canals (P> 0.05). The POV of the overall, coronal third, middle third and apical third of the root canals in the third group were greater than those in the other two groups (P < 0.05). Conclusions Using the same root canal filling method (LC), the sealing efficiency of root canal is not affected by the different root canal preparation methods. The group instrumented with ProTaper NiTi rotary files and filled by Warm vertical condensation has the best sealing efficiency.