In the current era, where identifying and nurturing scientific talents has become a strategic necessity for countries, student science festivals play a pivotal role. This research was conducted with the aim of performing a comparative study of China's Adolescent Science and Technology Innovation Contest (CASTIC) and Iran's Khwarizmi Youth Festival (student section), given the scientific-competitive nature of both events, to identify the structural, procedural, content, and output similarities and differences of these competitions to provide solutions for improving domestic festivals. This study was conducted using a comparative-analytical approach and George Bereday's four-stage method. Data were collected through purposive sampling of documents and official reports from the two festivals for the period 2021-2025 and were analyzed using qualitative content analysis. The findings revealed that although both festivals benefit from strong institutional support, they have fundamental differences in various dimensions. CASTIC, with its network structure and cross-sectoral participation, functions as a national talent identification system, whereas Khwarizmi has a centralized structure limited to the Ministry of Education. In terms of content, CASTIC focuses on technology, while Khwarizmi maintains a balanced approach incorporating humanities and cultural aspects. In the selection process, CASTIC employs an indirect model, while Khwarizmi utilizes a direct model. Additionally, CASTIC features a multi-layered reward system. Based on the findings, it is proposed to establish Iran's National Science and Technology Festival under the Vice Presidency for Science and Technology, as a structure in which the Khwarizmi Festival would operate as one of its accredited affiliated competitions.