Abstract: To meet the demands of future complex space missions, more advanced space propulsion systems are essential. Among these, nuclear thermal propulsion (NTP) systems offer high specific impulse, high thrust, and long operating times, making them an ideal choice for propulsion needs in manned deep space exploration, large interplanetary transportation, and space weapons platform maneuvering. The NTP system design often employs complex structures of tungsten-based uranium dioxide (UO₂-W) CERMET fuel elements, typically configured as honeycomb structures with multiple elongated coolant channels uniformly distributed throughout the fuel pellets. The intricate design of CERMET fuels, combined with the high melting point and hardness of tungsten, poses significant challenges for the molding and production of these fuel elements. Powder extrusion printing (PEP) technology, an emerging additive manufacturing technique, can achieve near-net-shaping of complex structures while reducing heat treatment temperatures, thereby significantly simplifying the fabrication process of cermet fuel elements. To address the developmental needs for complex-shaped UO₂-W CERMET fuels in NTP systems, PEP technology was utilized and the debinding and sintering processes were systematically optimized, enabling efficient fabrication and densification of complex-shaped fuels. By optimizing a wax-based binder formulation, a uniform feedstock with a UO₂ volume fraction of ≥55% was developed, effectively mitigating the segregation issues caused by the large density differences between UO₂ and W. The feedstock was processed using PEP technology, followed by n-heptane debinding (50 ℃, 12-72 h) and hydrogen sintering (1 900 ℃, 6 h holding time). Dense honeycomb-shaped fuel pellet samples were successfully fabricated, achieving a density of about 97% of the theoretical density. Microstructural characterization revealed uniform distribution of UO₂ and W without significant phase separation, with post-sintering W grain sizes of 5-8 μm and a hardness of about 520 HV. During the debinding process, n-heptane achieved a debinding rate of over 85%, while forming interconnected pore channels that provided ideal diffusion pathways for subsequent sintering. In the sintering stage, the hydrogen atmosphere effectively suppressed the formation of tungsten surface oxides, promoting grain boundary migration and pore closure. Optimization of the sintering process indicated that sintering at 1 900 ℃ resulted in an open porosity of <2.5%, although the grain size was relatively large. Furthermore, the corrosion resistance of the fabricated materials was indirectly inferred from their dense microstructure and low porosity, which minimize surface area exposed to corrosive environments. The hydrogen sintering atmosphere further enhances resistance by reducing oxide formation on tungsten surfaces. The low-porosity, uniform, and low-oxide-content surface state is crucial for improving the long-term corrosion resistance and service reliability of fuel elements in the high-temperature hydrogen coolant environment of NTP systems. This study validates the feasibility of PEP technology for the fabrication of complex-shaped nuclear fuels, overcoming the limitations of traditional processes in terms of complex shape formation and densification. Through the synergistic optimization of debinding and sintering processes, the densification of complex-shaped UO₂-W fuels was achieved, providing critical technical support for the development of NTP systems.