In　this　work,　we　demonstrate　the　systematic　and　delicate　geometry　control　of　Cu2O　nanocrystals　by　taking　advantage　of　the　selective　surface　stabilization　effect.　A　variety　of　Cu2O　architectures,　evolved　from　cubes　through　truncated　cubes,　cubooctahedrons,　truncated　octahedrons　and　finally　to　octahedrons,　were　achieved　by　simply　adjusting　the　added　PVP.　Based　on　the　understanding　of　the　intrinsic　structural　features　of　the　cuprite　Cu2O　and　PVP,　we　elucidated　the　underlying　shape　evolution　mechanism.　The　as-prepared　products　demonstrated　a　crystallography-dependent　adsorption　ability　with　methyl　orange　(MeO)　as　the　pollutant.　With　the　advantage　of　a　low　cost,　high　yield　and　straightforward　procedure　without　pre-formed　crystals　as　sacrificial　templates,　this　method　may　provide　a　good　starting　point　for　the　study　of　shape　construction　and　morphology-dependent　properties　of　other　nanocrystals.