Abstract: Driven by the goal of carbon neutrality, the proportion of new energy capacity has rapidly increased. In contrast, the randomness and volatility of new energy bring considerable challenges to the safety and operation of the power system. Power-to-X can convert renewable energy into other kinds of green fuels and use chemical energy to realize the consumption, storage, and transportation of electric energy, providing new ideas for storage and utilization in power systems. It also strengthens the coupling of various forms of energy and reduces carbon emissions in different fields, which is of great significance to the realization of low-carbon transformation. This paper comprehensively analyzed the key technologies in the Power-to-X, including the electrolysis for hydrogen production, CO₂ capture and the pathways of green hydrogen-to-X conversion. The development status of four typical Power-to-X pathways was analyzed and compared, including the power-to-methane, power-to-methanol, power-to-ether, and power-to-ammonia. In addition, this paper analyzed the main problems and challenges faced by Power-to-X from energy efficiency, carbon source and hydrogen production technology. Finally, this paper proposed corresponding measures and prospected the future development of Power-to-X.