Abstract: Temperature overshoot of the aging box will affect correctness of cable detection results. In order to reduce temperature overshoot of the aging box, methods to reduce temperature overshoot of RL100 aging box under different set temperature were studied. Results showed that at the same set temperature, self-setting temperature overcharge decreased when the initial temperature was lower and the size of self-setting heating interval would affect temperature overcharge after the self-setting. Test results could provide a reference for the subsequent selfsetting reduction of temperature overshoot in aging box.