Large-scale industrial wind turbines are well developed and widely implemented to harness kinetic energy of air flow for power production. However, little attention and effort was paid on developing miniature energy-efficient wind harvesters. In this work, a miniature harvester driven by air flow was manufactured by applying 3D printing technique and experimentally evaluated in a closed-loop wind tunnel. To simulate the experiment and to optimize the wind harvester design, three-dimensional numerical study was conducted. The model was validated by comparing the experimental results with the numerical ones first. Parametric study was then experimentally and numerically performed to examine the critical roles of (1) type of central part, (2) presence of end plates, (3) harvester length, (4) harvester diameter, (5) number of blades and (6) harvester installation orientation on static and dynamic performances of the designed harvesters. The optimal design was achieved according to the overall energy conversion efficiency, and the maximum efficiency achieved was eta(max) = 6.59%.