This paper takes the existing cooperation mechanisms of the BRICS countries as the research object, with a focus on analyzing the New Development Bank (NDB) and currency swap agreements (CSA). First, combined with the PESTEL framework, it examines the impact of the macro environment on the BRICS cooperation mechanisms from six dimensions: political, economic, social, technological, environmental, and legal, and reveals how various factors restrict or promote the advancement of financial cooperation. Then, based on institutionalist theory, it takes the synergistic effect of the NDB and CSA as a case to explore the role of formal and informal institutions in the construction of financial mechanisms. At the same time, it details the specific measures of BRICS financial cooperation, including project financing of the NDB, contingency reserve arrangements, CSA, the BRICS payment system, as well as supporting mechanisms such as financial regulatory coordination and trade and investment promotion, demonstrating a multi-level and multi-field cooperation framework. Finally, the paper discusses the future direction of the construction of BRICS financial mechanisms, emphasizing its significant role in enhancing the international financial discourse power of emerging economies and promoting the reform of global financial governance.