The invention discloses a live-line insulating boom type aerial leakage current alarm device, including an inner voltage measurement circuit, a mutual inductor signal preprocessing circuit and a leakage current detection circuit. The live-line insulating boom type aerial leakage current alarm device is based on the change of the leakage current detection device. The live-line insulating boom type aerial leakage current alarm device can be widely applied to the conventional 10kV insulating boom type aerial, and is small in structure, convenient to use and accurate to detect. The present invention overcomes the defects of the existing vehicle-mounted leakage current detection device, not only solves the problem that the vehicle-mounted leakage current detection device is cumbersome to install and affects the operation safety, and realizes real-time alarm during the operation of the live-line insulting boom type aerial. When the leakage current is greater than 500uA, the live-line insulating boom type aerial leakage current alarm device immediately alarms, is suitable for all types of 10kV insulating boom type aerials, overcomes the problem that the existing vehicle-mounted leakage current detection device is too large, complicated to install and inconvenient to use, and influences the operational safety, and achieves real-time online detection and guarantees the safety of workers.