The invention discloses a system and method for measuring a distorted electric field under an AC power transmission line. The system and method for measuring the distorted electric field under the AC power transmission line consists of a measurement module and a backstage software management module which communicate with each other through Bluetooth wireless communication. The measurement module is used for measuring and analyzing a distorted electric field under an AC power transmission line. The measurement module comprises a miniaturized power frequency electric field measurement probe, a middle connection assembly and a bottom pedestal. The middle connection assembly is used for connecting to the miniaturized power frequency electric field measurement probe and the bottom pedestal. The bottom pedestal consists of a signal collection processing circuit, a power supply circuit and a Bluetooth wireless communication module. The backstage software management module takes an intelligent mobile phone terminal carrying an Android system as a carrier for displaying, storing and exporting distorted electric field testing data. The system and method for measuring distorted electric field under the AC power transmission line can reduce affects on a tested electric field due to introduction of the measurement sensor probe and proximity of testing staff and can reduce measurement errors.