Abstract: Electron and ion sources based on thermionic emission filaments are widely used in various space applications, such as ionization sources for ion thrusters, neutralizers for different types of electric thrusters, ionization sources for leak detectors and mass spectrometers, and ionization vacuum gauges. The electron sources in these devices face stringent requirements such as high emission current, resistance to vibration and thermal shock, and long lifespan. The existing thermionic emission filaments primarily include tungsten filaments, thoriated tungsten filaments, and iridium-yttrium oxide filaments. Among these, thoriated tungsten filaments exhibit excellent emission performance but are radioactive. Tungsten filaments have low emission efficiency and poor oxidation resistance. Iridium-yttrium oxide filaments are non-radioactive and possess good oxidation resistance, but their emission performance is relatively low. In helium mass spectrometers and ionization vacuum gauges, traditional iridium-yttrium oxide filaments mostly use a straight-wire structure, with emission currents typically ranging from 0.1 to 10 mA. This study designs a spiral iridium-yttrium oxide filament for space applications, which significantly improves the emission performance, with a single filament emission current exceeding 200 mA. At the same time, an insulating support structure is introduced for the filament, which significantly enhances its vibration resistance and continuous working ability. The filament partially contacts the support structure both during operation and non-operating periods, achieving spatial positioning and stabilization through this “soft contact”. This prevents performance degradation caused by solder joint detachment or high-temperature deformation, thereby improving the filament’s adaptability and stability under the harsh conditions of space. The prepared spiral filament has passed the qualification test and can work continuously for more than 2300 hours. This study demonstrates the excellent performance of iridium-yttrium oxide filaments and expands its application prospects in the aerospace field.