Objective To investigate the application value of low-dose single-source dual-energy CT and MRI in diagnosis of Achilles tendon rupture. Methods A total of 42 patients with suspected Achilles tendon rupture underwent dual-energy CT and MRI scanning.36 cases of Achilles tendon rupture and 6 cases of normal patients were tested. In 36 cases of Achilles tendon rupture patients, 25 patients with complete Achilles tendon rupture were diagnosed by MRI. 11 patients with partial rupture, 7 patients were diagnosed by follow-up MRI, 4 patients were diagnosed by operation and MRI. 6 patients with normal tendons were diagnosed as calcaneal fracture, the fracture line involved the attachment of the Achilles tendon. The operation was clear and no rupture of Achilles tendon was observed in operation. Two-dimensional and three-dimensional image post processing, such as multiplanar reconstruction(MPR), tendon 3D volume rendering(VR), to show Achilles tendon, dual-energy CT virtual decalcification imaging for diagnosis of ankle bone edema, calculation of tear and normal tendon CTD, CTD=CTmean135-CTmean80. Results 99KeV soft tissue image window combined with MPR can diagnose the complete rupture of Achilles tendon. The sensitivity and specificity of diagnosis of complete rupture of Achilles tendon were 100% and 100%, respectively.The sensitivity and specificity of diagnosis of partial rupture of Achilles tendon were 81.8% and 100%, respectively, on VR imaging, the sensitivity and specificity of diagnosis of complete rupture of Achilles tendon were 100% and 100%, respectively. The sensitivity and specificity of diagnosis of complete rupture of Achilles tendon were 63.6% and 100%, respectively, on virtual calcium removal imaging, the sensitivity and specificity of diagnosis of bone edema were 77.5% and 80% respectively. The sensitivity and specificity of MRI diagnosis of complete and partial Achilles tendon rupture and bone edema patients were 100% and 100%, respectively. The sensitivity and specificity of bone fracture patients were 40% and 100%, respectively. Conclusion Dual-energy CT imaging can effectively diagnose complete Achilles tear and partial Achilles rupture, and its performance of finding fracture was better than MRI, while finding bone edema was worse than MRI