A comprehensive understanding of the microscopic reaction mechanisms at the gas-solid-liquid electrochemical interfaces is urgently required for the development of advanced electrocatalysts applied in burgeoning sustainable energy conversion systems. In-situ synchrotron radiation Fourier transform infrared (SR-FTIR) spectroscopy is one of the most powerful techniques for investigating the evolving dynamics of reactive intermediates during electrocatalytic reactions. In this review, we methodically summarize the recent progress in the research of dynamic mechanisms for valuable electrocatalytic reactions based on in-situ SR-FTIR methodology. Moreover, the merits and drawbacks of SR-FTIR spectroscopy, the design principles of infrared beam setups and in-situ cells, as well as the in-situ measurement criteria are also discussed in detail. Lastly, the potential challenges and opportunities in this field are prudently stated. This review is expected to stimulate a broad interest in the material science and electrochemistry communities for exploring the dynamic mechanisms of prominent catalysis at the atomic/molecular level by using SR-based spectroscopy.