Medical Isotope Production Reactor is a specialized solution reactor designed to alleviate global supply shortages of medical isotopes. The behavior of microbubble swarms generated from radiolytic gas production during the fuel solution irradiation plays a critical role in the operational stability and thermal–hydraulic characteristics of the reactor. This study aims to experimentally investigate the behavior characteristics of microbubble swarms, focusing on their macroscopic phenomena and characteristic data. The electrolytic method was employed to simulate the gas generation state within the reactor core, while high-speed photography was utilized to capture the dynamic behavior of bubbles within the experimental setup. Then, image processing software was applied to analyze the data, revealing significant findings regarding the behavior characteristics of microbubble swarms. Results indicate the presence of bubble circulation phenomena within the device, along with uneven gas production on the cathode surface. In the middle of the device, the feature number and the feature velocity of bubble swarms in the vertical bubble band region were found to be significantly higher than in the non-bubble region. Additionally, in the non-bubble region, the relationship between the feature velocity and the feature diameter adheres to Hadamard–Rybczynski equation. This research provides critical insights that may enhance reactor design and operational efficiency in the production of medical isotopes.