A flexible dual-stopband terahertz metamaterial filter with polarization insensitivity is proposed and designed. CST 2015 simulation software is used to simulate the structure of the designed metamaterial filter. To further study transmission characteristics of the metamaterial filter, we simulate the electric field intensities and surface current distributions of the metamaterial filter, respectively. To verify the validity of simulation results, we prepare a metamaterial filter sample by using the micro-manufacturing technology, and measure the transmission performance of the filter by using the terahertz time-domain spectroscopy (THz-TDS) system. The results show that the filter has two stopbands with 3 dB bandwidth of 15 GHz and 10 GHz at resonance points when the resonance frequencies are 0.131 THz and 0.182 THz, respectively. The transmission coefficient S21 at the two resonance points can reach -43.56 dB and -48.76 dB, and the filter shows good stopband characteristics. The measured results accord with the simulated ones.