The cable very low frequency dielectric loss(VLF-TD) test technology has just started in China.The IEEE Std 400.2—2013 VLF-TD criterion is not fully applicable to localized XLPE cable of China.It is extremely urgent to carry out research on cable VLF-TD test.Therefore, the effectiveness of VLF-TD test for water tree degradation detection is verfied by accelerating water tree aging test and carries out on-site measurement.The 252 sets of data measured are classified and it is found that the cable line with a negative dielectric loss rate is in a state of attention or abnormality, and is mostly in an abnormal state.And the fluctuation value of the dielectric loss can more clearly and intuitively reflect the running state of the cable.Therefore, in addition to the three existing criteria of VLF-TD, the new characteristic quantity reverse dielectric loss change rate and extreme difference of dielectric loss are proposed, and the Korean Skirt dielectric loss criterion is absorbed, which is finally improved.The VLF-TD test criterion system provides a reference for the formulation of the VLF-TD aging state evaluation procedure for distribution cables in China.