In order to know the health condition of the cable after prolonged use, the cable state is evaluated by logarithmic normal distribution and Weibull distribution. The distribution of the dielectric loss and partial discharge of the cable is assumed to conform to two different distributions. With the help of Matlab numerical simulation software, the aging data accumulated by a power supply company through oscillatory wave test in recent years is fitted. The comparison between the two fitting results shows that the logarithmic normal distribution is more accordant with the distribution of aging parameters of cables. Three levels of cable status are set, and a state assessment model is established and used to evaluate the state of 10 kV cable in a power company. The research results will help to understand the changes in the state of the cable during the operation and put forward the corresponding maintenance plan. This work is supported by Science and Technology Project of State Grid Corporation of China (No. GCB17201400106).