1) The system uses the thermal network method based on Ohm's law of the thermal flow field to calculate the current carrying capacity of the cable. The concept is clear and easy to understand and master. It can not only be used to solve the thermal field of the cable, but also can be used to obtain the cable conductor temperature in the case of monitoring the surface temperature of the cable, or calculate the ambient temperature at this time according to the actual load and surface temperature of the cable, so as to obtain the current environment The rated load of the cable under the conditions. 2) Experiments have proved that using this cable calculation method, the maximum deviation between the calculated conductor temperature and the actual measured value within the range below 90 ℃ does not exceed ± 3 ℃; near the maximum operating temperature of the cable conductor, the measured conductor steady-state operating current and calculation The difference in current value is less than ±1%. 3) Use this software to carry out related cable selection calculation and operation verification. The process is convenient, fast and accurate. It not only saves a lot of time for cable selection and maintenance personnel, but also provides a reliable basis for selecting and mastering the cable operation status. It is more accurate, and it is also very helpful to the evaluation of the operating life of the cable.