Abstract: Currently, most research on the preparation of superhydrophobic surfaces with anti-frosting micro-nano structures focuses on the frosting process at horizontal angles. To further investigate the frosting and defrosting characteristics of small-scale special heterogeneous surfaces on vertical walls, this study presents a super-hydrophobic surface featuring a hierarchical micro-nano hollow square column array (HSCA), designed for passive defrosting control through additive manufacturing. In order to gain a comprehensive understanding of the frost formation process and assess the defrosting performance of this HSCA surface, a visualization system was developed to facilitate an experimental investigation into the frost formation and melting processes, focusing on metrics such as frost coverage, initial and full frost time instants, and surface heat flux. The experimental results reveal that, in comparison to hydrophilic and super-hydrophobic flat surfaces, the hierarchical micro-nano structures make the condensation nucleation of humid air occur further away from the surface, particularly around the tops of the square columns. The experimental results show that frost growth and thawing on the superhydrophobic hollow square pillar array progress from the periphery to the center, with complete frost detachment occurring during thawing. The time to reach full frost coverage is 32.5% longer than on the superhydrophobic flat surface, while the time for complete frost melting and draining is 25% shorter. The hierarchical micro-nano structures cause the condensation nucleation of humid air to occur further from the surface, particularly around the tops of the square pillars. This unique behavior effectively hinders the spread of freezing waves and slows the growth of the frost layer, resulting in a discretely distributed frost layer on the hierarchical structure's surface. Consequently, the superhydrophobic surface significantly improves anti-frost performance and accelerates the rates of melting and discharge during the frost melting stage.