With the emergence of advanced welding technology and novel internal structure development for nuclear fuel elements, the existing non-destructive testing X-ray radiography has gradually failed to satisfy the actual requirements. In this communication, we firstly introduced the NDT necessity and difficulties of typical rod-shaped fuel elements. Then the traditional radiography test, DR(digital radiography), DR based on micro-focus X-ray source, and micro-CT (computed tomography) imaging of simulation fuel rods were carried out. By analyzing the different imaging characteristics and defects recognition, the experimental results showed that the DR based on micro-focus source achieved a balance between detection efficiency and detection accuracy, and might replaced the traditional radiography test standard. Finally, the imaging advantage and application direction of micro-CT were concisely discussed. The micro-CT and DR involved in this paper has a certain reference value and significance for the development of nuclear elements in China.