Abstract: Under the strategic goal of “dual carbon”, Carbon Capture, Utilization, and Storage （CCUS） is a key pathway to achieving green, low-carbon, and sustainable development. Among various CCUS approaches, electrochemical CO₂ reduction （CO₂ER） is considered highly promising. This technology uses clean electricity to directly convert captured CO₂ into value-added chemicals—such as carbon monoxide, ethylene, and methanol—under ambient temperature and pressure. It not only enables the resource utilization of CO₂ but also offers a practical way to integrate renewable energy, providing clear advantages over other carbon utilization methods. At present, research on CO₂ER is still largely limited to the laboratory, and significant progress is needed for industrial application. Membrane electrode assembly （MEA） electrolyzers, a type of low-temperature CO₂ER reactor, have advantages such as low ohmic resistance, compact design, and scalability, making them a promising option for large-scale CO₂ electrolysis. However, scaling up MEA electrolyzers presents several major challenges. Their complex internal multiphase transport environment is prone to electrode “flooding” （liquid water accumulation at the cathode） and “salt precipitation” （salt crystallization at the cathode）. These issues not only reduce catalyst stability but also hinder CO₂ transport to active sites. As electrode size increases, uneven distribution of reactants, current density, and product concentration becomes more significant, both across the electrode surface and between stack units. In addition, heat buildup within the electrolyzer intensifies, posing risks to stable operation. This review begins with the basic working principles of CO₂ER in MEA electrolyzers and systematically examines the key factors limiting their large-scale industrial deployment. It focuses on four main areas: long-term catalyst durability, operational stability of the electrolyzer, engineering scale-up from laboratory to industrial level, and system-level optimization through modeling. By integrating and analyzing the latest research advancements in this field, this paper aims to provide relevant references for the industrial development of CO₂ electrolysis.