A nonamer metamaterial composed of nine split ring resonators with different orientations was experimentally and numerically researched in terahertz band. The nine split rings were arranged spirally. From the first split ring, the subsequent split rings were rotated anti-clockwise by 40°. Generally, the split ring resonator was polarization-dependent. It was found that split rings oligomer, which can produce multiple resonance modes, was polarization-independent owing to the near-field energy coupling. The split rings oligomer composed of polarization-dependent resonators exhibited a polarization-independent effect, which enriched the design idea of traditionally uncoupled metamaterial composed of disperse resonators, and induced a new path for terahertz functional devices, like optical switch, modulator, filter and so on.