The invention relates to a detection method partial discharge of electrical equipment and a device thereof. The detection method comprises the following steps of: erecting a measuring antenna in the position which is 20-30m away from the equipment to be detected, measuring an electromagnetic wave electric field component radiated from the electrical equipment, transmitting the measured signal waveform of the electromagnetic wave electric field component into a digital storage oscilloscope for storage, transmitting the signal waveform from the digital storage oscilloscope to a computer via a communication cable, performing Fourier decomposition on the signal waveform by application software of the computer to get a frequency spectrum characteristic curve of radiated electromagnetic waves, and performing contrastive analysis on the frequency spectrum characteristic curve according to the corresponding relation between a 1GHz-3GHz ultra-high frequency component and the partial discharge characteristic of the electrical equipment so as to identify and evaluate the partial discharge characteristic of the detected electrical equipment. The detection method has the following advantages: 1-3GHz ultra-high frequency signals of the radiated electromagnetic waves generated by the partial discharge are measured through an ultra-high frequency detection method, so that the detection is less affected by external interference signals, and reliability and sensitivity in detection of the partial discharge can be greatly improved.