Abstract: Traditional chemical fuel propulsion is limited by the upper limit of energy release in chemical reactions,and its propulsion efficiency has approached the theoretical peak,making it difficult to meet the stringent requirements of future deep exploration missions for spacecraft's high-speed boost,long-term stable operation in orbit,and large payload carrying.Against this backdrop,nuclear electric propulsion and nuclear thermal propulsion have become the focus of research in the field of aerospace propulsion,and the hybrid dual-mode propulsion system,which combines both modes,is recognized as the core direction future technological development. This paper provides a systematic review of the current application progress of nuclear electric propulsion,nuclear thermal propulsion,and nuclear electric-nuclear thermal dual-mode propulsion,and evaluates the application feasibility of magnesium hydride as a key homogeneous working substance. Nuclear electric propulsion,with lithium,magnesium,and other metals as working substances,is suitable for long-duration continuous acceleration tasks in deep space exploration due to its high specific impulse and long life advantages. Nuclear thermal propulsion,with hydrogen as the working substance,provide large thrust and moderate specific impulse,making it suitable for rapid adjustments of spacecraft orbits. The dual-mode propulsion system integrates the advantages of both propulsion methods and achieves efficient propulsion of spacecraft through flexible switching of modes,but it still faces technical bottlenecks such as complex equipment structure design and difficulties in coordination between dual-working substance storage and supply. Decomposition of magnesium hydride can produce products that match the needs of nuclear thermal propulsion（H₂） and nuclear electric propulsion（Mg）,and using it as a homogeneous substance could potentially reduce the system's weight by more than 30% compared to traditional dual-working substance schemes. However,it still needs to overcome key problems such the lack of hydrogen release kinetics data under high back pressure and the efficient design of tanks under low gravity conditions. Future efforts should continue to deepen research in related fields to promote the application of such new propulsion technologies to actual space missions.