The embodiment of the invention, which belongs to the field of electrical equipment, provides an insulation defect detection device and method for an electrical device. The insulation defect detectiondevice comprises a quantum sensor for detecting distribution characteristics of an electric field and/or a magnetic field intensity of an electric device, a laser generator for emitting laser light by the quantum sensor to excite the quantum sensor, a microwave transceiver for transmitting a microwave signal to the quantum sensor and receiving a microwave signal fed back by the quantum sensor, anelectron spin resonance spectrometer for starting the laser generator and the quantum sensor and acquiring distribution characteristics of the electric field and/or magnetic field intensity of the current transformer in space based on the fed back microwave signal, and a processor for determining whether the electrical device has a defect based on the detected distribution characteristics and determining the type of the defect if the electrical device has a defect. With the insulation defect detection device, the distribution characteristics of the electric field and the magnetic field of theelectrical device can be detected and the defect type of the electrical device is determined.