The invention relates to a thermistor-based environmental temperature detecting device for power capacitors. The thermistor-based environmental temperature detecting device comprises a thermistor temperature measuring module, an information processing module, a wireless module and an alarm display module. The thermistor temperature measuring module is connected with the information processing module, and the wireless module is connected with the information processing module and the alarm display module. The thermistor temperature measuring module comprises a series circuit, and the series circuit comprises a direct-current power source, a direct-current ammeter, a thermistor bank and a protective resistor. The thermistor bank comprises six thermistors, and the six thermistors are connected with one another in parallel and can be respectively mounted on six surfaces of each power capacitor. Alarm effects can be realized under the condition of problems of any surface of each power capacitor. The thermistor-based environmental temperature detecting device has the advantages of high detection sensitivity and reliability, real-time monitoring, low cost, convenience in follow-up circuit maintenance, and the like.