This paper proposes a Polarized Rotating Surface (PRS) in which the middle layer is composed of two orthogonal open resonant rings of different sizes, which is also an innovation of this structure. This structure can convert TE/TM waves into TM/TE waves orthogonal to them, and the polarisation conversion efficiency remains above 99% within the bandwidth. Therefore, the decoupling method of this structure is different from the traditional decoupling by blocking electromagnetic wave propagation, and different from the introduction of additional paths for neutralization and decoupling. Instead, polarisation isolation is achieved by converting electromagnetic waves into their orthogonal waves. Not only that, through electromagnetic simulation, the proposed polarisation rotating surface can reduce the electromagnetic coupling between two ultra-wideband horn antennas whose centers are 1 m apart in the range of 5GHz ~19GHz by an average of 20dB and a maximum of 30dB. The final experimental results demonstrate that, within the operating frequency band, this PRS can reduce the coupling between ultra- wideband array antennas by an average of 20dB.