The notorious growth of sodium dendrites and significant volume fluctuations have posed substantial challenges to the practical application of sodium metal anodes. In this work, an aerogel composed of MgF₂ nanoparticles (NPs) onto a three-dimensional (3D) printed reduced graphene oxide (rGO) (MgF₂/rGO) monolith was employed as a scaffold for sodium metal anodes. During the initial discharge process, the MgF₂ NPs underwent an electrochemical in-situ conversion into NaF and sodiophilic Mg NPs, which act as the Na metal nucleation centers and contribute to the formation of a stable solid electrolyte interface (SEI) layer. Benefiting from these synergistic effects, the 3D printed MgF₂/rGO electrode exhibits a high Coulombic efficiency of 99.49% after 1200 cycles at 0.5 mA·cm⁻² with 1 mAh·cm⁻². It also shows a long cycle lifespan of 2500 h with a high capacity of 10 mAh·cm⁻² at 5 mA·cm⁻². Moreover, when assembled into a full cell with a Na@MgF₂/rGO anode and a Na₃V₂(PO₄)₃@C-rGO cathode, the cell delivers an extended cycle life of 3500 cycles at 1 C, preserving a reversible capacity of 86.98 mAh·g⁻¹. This work paves the way for utilization of 3D printed metal-fluorides to enhance the electrochemical performance of the sodium metal anodes.