Electrochemical reactors, powered by renewable electricity, have garnered widespread attention for chemical synthesis due to their low energy consumption and pollution‐free features. However, the inherent design flaw of traditional electrochemical reactors has persistently hindered the advancement of electrochemical synthesis, as they result in low product concentrations, low purity, and continuous production issues. As a novel electrochemical reactor, the porous solid‐state electrolyte (PSE) reactor is elaborately designed to overcome the limitation by enabling the direct and continuous synthesis of pure products, possessing a modular and scalable structure with high efficiency, safety, and long stability. In this work, first, the distinctive design of the PSE reactor, highlighting its structural features, core components, and variable configurations, is introduced. Furthermore, the configuration‐relevant applications in electrosynthesis, such as formic acid, acetic acid, and hydrogen peroxide (H2O2) production, are summarized. Integrated applications are also discussed, along with potential domains for improvements and optimization. Finally, the future developmental directions of the PSE devices are thoroughly explored. By addressing its unique design attributes, showcasing its capabilities, and envisioning prospective refinements and diverse applications, the aim is to boost the progression of this transformative technology toward widespread commercialization and industrial adoption, thereby revolutionizing sustainable electrochemical synthesis.