The inadvertent current carrying capacity of power cable is bound to be affected by many factors, such as air temperature, ground temperature, backfill sand, soil covering depth, grounding mode, soil thermal resistance coefficient, number of circuits, ventilation design, laying mode, groundwater, metal sheath circulation, layout mode, solar radiation, surrounding heat source . This paper analyzes the common factors in the work, and expounds the mode of flow promotion through the analysis and numerical calculation of power cable ampacity. It also compares the effects of the two methods, hoping to provide new ideas for the follow-up research on related issues.