This review article focuses on the development and optimization of RuO₂-based catalysts for the electrocatalytic oxygen evolution reaction (OER) in acidic media. The OER is a critical step in proton exchange membrane water electrolysis (PEMWE), which is essential for sustainable hydrogen production. However, the slow kinetics, poor catalyst stability, and high cost of current OER catalysts limit the efficiency of PEMWE. RuO₂ has emerged as a promising alternative to iridium-based catalysts due to its excellent electrocatalytic activity and pH adaptability. The article discusses two main reaction mechanisms of OER: the adsorbate evolution mechanism (AEM) and the lattice oxygen oxidation mechanism (LOM). It highlights the challenges and limitations of RuO₂, such as over-oxidation and dissolution, and reviews various strategies to enhance its activity and stability, including heterostructure construction, heteroatom doping, defect engineering, and morphology engineering. These strategies aim to improve the binding energy of oxygen intermediates, adjust the electronic structure, and enhance the catalytic performance and durability of RuO₂. The article also provides insights into the current challenges and future prospects for the practical application of RuO₂-based catalysts in PEMWE, emphasizing the need for advanced techniques to study reaction mechanisms and accelerated deactivation test systems to evaluate long-term stability. Overall, the review underscores the potential of RuO₂-based materials for OER and the ongoing efforts to address their limitations through interdisciplinary research and technological advancements.This review article focuses on the development and optimization of RuO₂-based catalysts for the electrocatalytic oxygen evolution reaction (OER) in acidic media. The OER is a critical step in proton exchange membrane water electrolysis (PEMWE), which is essential for sustainable hydrogen production. However, the slow kinetics, poor catalyst stability, and high cost of current OER catalysts limit the efficiency of PEMWE. RuO₂ has emerged as a promising alternative to iridium-based catalysts due to its excellent electrocatalytic activity and pH adaptability. The article discusses two main reaction mechanisms of OER: the adsorbate evolution mechanism (AEM) and the lattice oxygen oxidation mechanism (LOM). It highlights the challenges and limitations of RuO₂, such as over-oxidation and dissolution, and reviews various strategies to enhance its activity and stability, including heterostructure construction, heteroatom doping, defect engineering, and morphology engineering. These strategies aim to improve the binding energy of oxygen intermediates, adjust the electronic structure, and enhance the catalytic performance and durability of RuO₂. The article also provides insights into the current challenges and future prospects for the practical application of RuO₂-based catalysts in PEMWE, emphasizing the need for advanced techniques to study reaction mechanisms and accelerated deactivation test systems to evaluate long-term stability. Overall, the review underscores the potential of RuO₂-based materials for OER and the ongoing efforts to address their limitations through interdisciplinary research and technological advancements.