A highly-tunable wide-angle metamaterial absorber with perfect absorption and polarization-insensitivity was introduced and investigated. Simulative results show the maximum absorption reaches up to 99.9% at 5.8 μm and the absorber can be tuned arbitrarily in the range of 3.4 μm to 8.6 μm with the absorption remaining above 95% by changing its geometric parameters. The absorber remains absorptivity of over 95% with incident angles below 80° under transverse magnetic(TM) polarization and that of over 92% below 60° under transverse electric(TE) polarization. Furthermore, the absorber is polarization insensitive with polarization angle varying from 0° to 90°.