Surface structure of polymer material is tightly connected to its application field, performance and appearance. Surface morphology construction down to nanometer scale has been an important topic in polymer processing, among different methods to achieve controllable and precise structure, template method has been known to be rather commercially available and technically fulfilling. Anodic aluminum oxide (AAO) is used in our study to fabricate nano array on PVDF surface via a melt-infiltration method, featuring the flexibility of template parameter, great repeatability and regular through pore structure of AAO, and the processability of polymer PVDF, to study surface morphology influence on water wettability. Experiment results imply that under proper melting condition, polymer melt can spontaneously infiltrate AAO pores with a minimum diameter of 30 nanometer and replicate the structure of the template to form a uniform fiber array after etching the template. And as the aspect ratio increase, nano array on the surface tends to form agglomeration which takes the shape of micrometer scale pattern, increasing air pocket size and water wettability. While sample with high aspect ratio gained water contact angle as high as 131°, sample with low aspect ratio reached 20° in contact angle, showing a wide adjustable water contact angle range through changing surface nano array aspect ratio, demonstrating surface angle control via surface morphology alteration accessible.