The invention discloses a metal nano-brick array structure and application of the structure as a polarization beam splitter. The metal nano-brick array structure comprises a substrate and a metal nano-brick array on the substrate, wherein the metal nano-brick array is formed by the arrangement of metal nano-brick units; each metal nano-brick unit comprises a plurality of metal nano-bricks, and themetal nano-bricks are arranged in a row in an equal interval manner along the width direction of the metal nano-bricks and have the same size; and the metal nano-bricks are rectangular and have a sub-wavelength size. By utilizing the metal nano-brick array structure as the polarization beam splitter, the beam splitting efficiency above 90% can be achieved in a visible light waveband of 490nm-590nm, and the beam splitting efficiency above 80% can be achieved in a visible light waveband of 475nm-765nm. Besides, the polarization beam splitter utilizing the metal nano-brick array structure further has the advantages of small volume, lightness, compact structure, easiness in integration and the like.