In order to solve the problem that high temperature of cables in comprehensive pipe gallery leads to disaster, the temperature field distribution and influencing factors of cables in comprehensive pipe gallery during operation are studied in this paper. Based on the finite element numerical model established by ANSYS, the distribution rule of temperature field of cable in pipe gallery is studied, and the influence of the distance between cable core layers, the distance between support layers and the current on the distribution of temperature field of cable is analyzed. The results show that when the distance between cables and support layers is greater than 0.6 m, the influence on the temperature distribution of cables is small. The cable spacing is suggested to be 0.2 m, and the distance between support layers is suggested to be 0.2 m. The main influence radius of cable temperature field in pipe gallery is 0.83 m, which is independent of cable current, cable spacing and support layer spacing. The electric flux of the cable is an ExpAssoc function related to the temperature of the cable during operation and the distance between the cable cores. The distribution of temperature field of the cable can be monitored online to calculate the size of the cable flow and monitor the load to ensure the safe operation of the cable.