The invention discloses a double-layer butterfly antenna and belongs to the field of local discharge UHF detection technologies. The double-layer butterfly antenna comprises a dielectric substrate, afirst butterfly patch arranged on the upper surface of the dielectric substrate and a second butterfly patch arranged on the lower surface of the dielectric substrate, wherein a first microstrip lineconnected with the first butterfly patch is arranged in the middle of the upper surface of the dielectric substrate, a second microstrip line is arranged in the middle of the lower surface of the dielectric substrate, the two ends of the second microstrip line are connected with the second butterfly patch and the first microstrip line respectively, the first microstrip line and the second microstrip line are etched on the upper surface of the dielectric substrate and the lower surface of the dielectric substrate respectively, the two ends of the first butterfly patch are provided with notchesrespectively, and the two ends of the second butterfly patch are provided with notches respectively. Through the double-layer butterfly antenna, on the premise of guaranteeing antenna miniaturization,more electromagnetic wave signals can be received, and the detection sensitivity and anti-interference capability of a UHF detection system are improved.