The invention discloses a portable terminal for preventing accidental entry into a charging interval. The terminal comprises a transmitting module placed at a central portion of a service site and transmitting a signal to a receiving module; the receiving module, configured to receive a signal, and the signal is sent to a microprocessor MCU after being processed, filtered, and detected and conditioned; the microprocessor MCU, processing the conditioned signal and obtaining the actual distance between the receiving module and the transmitting module, and comparing the actual distance with the set safety distance, if the actual distance exceeds the safe distance range, the microprocessor MCU controls an alarm to start; and the alarm, configured to emit sound and light alarm. The receiving module, the microprocessor MCU and the alarm are integrated on one terminal and worn on the maintenance personnel, and the distance value of the actual distance beyond the safety distance is proportional to the intensity of the sound and light alarm emitted by the alarm. The portable terminal for preventing accidental entry into charging interval greatly improves the safety of the maintenance work,and has the advantages of small volume and convenient carrying.