Existing detection techniques for partial discharge based on transformer bushings have low sensitivity and cannot detect timely, while ultra-high frequency(UHF) technology has high anti-interference ability and can achieve contactless detection. UHF detection technology for bushing partial discharge detection method is proposed. A 35 kV bushing partial discharge simulation model is established and a partial discharge test is performed for different types of defects. The conclusions include that both oil-impregnated paper amid the capacitances and the oil channel are effective paths for UHF electromagnetic wave propagation. Transverse magnetic wave(TM) is greatly attenuated during the propagation process(from -16 dB to -5 dB). The initial component of the transverse electric wave(TE) is less than 1% and the main component is the transverse electromagnetic wave(TEM). The main energy in the UHF band concentrates in the lower frequency domain, and the partial discharge of different defect types of the bushing corresponds to different characteristic spectra. The contactless UHF sensor of the bushing can realize the live detection of the bushing, thereby ensuring the safety and reliability of the power transformer operation.