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• A large-area, periodic porous Au nanoparticle (PGNP) array is fabricated. • The morphology of the PGNP can be easily tailored. • The PGNP arrays exhibit outstanding SERS activities and excellent reproducibility. • The PGNP arrays show excellent polarization independence for SERS performances. Porous noble metal nanoparticles have attracted great attention in surface enhanced Raman scattering (SERS) applications due to the presence of high-density and built-in hotspots. Herein, we develop a facile route to fabricate large-area, periodic porous Au nanoparticle (PGNP) array based on ultra-thin alumina membrane (UTAM) incorporated with annealing and dealloying techniques. The size and ligament of the PGNP can be easily tailored by changing the thickness of the deposited Au/Ag film and the dealloying time. The PGNP array exhibits excellent uniformity and high sensitivity in SERS analysis due to the periodic structure and the enormous built-in hotspots. A large Raman enhancement factor (EF) of 1.4 × 107 is achieved with a relative standard deviation (RSD) less than 6.6%. Furthermore, experimental results and numerical simulations demonstrate that this PGNP array substrate exhibit polarization independence. The facile and controllable fabrication strategy makes the substrate promising for practical applications in many SERS-based qualitative and quantitative analyses. [ABSTRACT FROM AUTHOR]