In order to evaluate the effect of fireproof belt on cable load and temperature,a 220 kV cable carrying capacity verification platform is built in the laboratory to analyze the current carrying capacity and monitoring temperature of high voltage cable for different kinds of fireproof belt. The experiment and theoretical analysis shows that: the temperature gap ratio between of out-and-in fireproofing strip and metal wire core and environment for ceramic fiber, PVC and rubber fireproof are 29.44%, 4.74% and 4.52%, meaning that rubber fireproof belt has the best heat dissipation effect, the PVC fireproof belt is slightly less than that of rubber fireproof belt, and the heat dissipation performance is far better than that of ceramic fiber fireproof belt. Wrapping fireproof belt will reduce cable carrying capacity, the carrying capacity wrapped with ceramic fiber,PVC and rubber fireproof are 81.9%,96.2% and 96.4% of unwrapped cable. When the cable reaches maximum allowable load, the surface temperature of ceramic fiber, PVC and rubber fireproof are 38.7 ℃,52.7 ℃and 52.9 ℃ respectively, lower than the maximum allowable temperature of cable sheath unwrapped fireproof belt. Therefore, in order to ensure the core temperature does not exceed 90 ℃ with maximum carrying capacity in the distributed optical fiber temperature measuring system, the alarm threshold should be reduced accordingly.