Abstract: Vacuum micro-nanoscale electronic devices （VMNEDs）, a class of emerging devices combining vacuum electronics with nanotechnology, have garnered significant attention for their excellent high-speed performance, high-temperature tolerance, radiation resistance, and extreme-environment compatibility. This review systematically analyzes the evolution, theoretical frameworks, technological breakthroughs, and future trajectories of VMNEDs, highlighting their potential to merge traditional vacuum tube advantages with solid-state device miniaturization. Leveraging field emission theory and nanoscale vacuum channel designs, VMNEDs enable ballistic electron transport under atmospheric pressure, achieving low-voltage operation （below 10 V） and ultrahigh-frequency responses （cutoff frequencies up to 0.46 THz）. Structural innovations, categorized into planar and vertical architectures, exhibit distinct merits: planar devices （e.g., coplanar graphene-based transistors） achieve sub-120 mV/dec subthreshold swing and CMOS compatibility, while vertical configurations （e.g., Spindt cathodes, internal/external channel structures） deliver high current densities （>3000 A/cm²） and robust stability at 600 ℃ or under 30 krad radiation. Material advancements further drive performance: selectively etched metallic nanotips achieve field enhancement factors exceeding 6000, wide-bandgap semiconductors （SiC, GaN） integrate low electron affinity with intrinsic radiation hardness, and low-dimensional materials （carbon nanotubes, graphene） optimize emission efficiency through surface functionalization of work functions. Despite progress, challenges remain in process uniformity, long-term reliability （e.g., tip degradation, material oxidation）, and CMOS integration. Recent nanofabrication breakthroughs, such as umbrella-shaped cathodes and vertical air-bridge structures, have improved current density and switching speeds. Experimental validation under extreme conditions（including 1×10¹⁴ n/cm² neutron irradiation and >500 ℃ operation）confirms VMNED resilience, positioning them for space applications. Emerging uses span high-frequency communication, deep-space ion propulsion, radiation-hardened electronics, and biomedical sensing: GaN-based nanoscale air-channel diodes show nanosecond response times, while vacuum-gated transistors maintain performance after radiation exposure. Future research should focus on material hybridization （e.g., heterostructured cathodes）, 3D structural innovations, and scalable manufacturing to address limitations. Integrating VMNEDs with MEMS and photonic circuits unlocks multifunctional, high-reliability systems for aerospace, energy, and quantum technologies. This review synthesizes theoretical insights and empirical achievements, providing a roadmap for advancing VMNEDs toward practical implementation in next-generation extreme-environment electronics.