In recent years, with the rapid emergence of Artificial Intelligence Generated Content (AIGC) platforms such as ChatGPT and Midjourney, the traditional content creation process has been completely transformed. Young designers, as the group with the highest acceptance of AIGC platforms, play a pioneering role in this technological revolution. However, the factors influencing the continued usage of these platforms by young designers remain unclear, which is crucial for the commercial sustainability of AIGC platforms. To address this research gap, this study constructs the AIGC Continuous Usage Model (ACUM) based on the Expectation Confirmation Model (ECM) and the Technology Acceptance Model (TAM), analyzing the key factors influencing the continued usage of AIGC platforms by young designers. The study encompasses various subfields of design, including product design, visual design, interior design, and landscape design. We focused our research on the well-known platforms ChatGPT and Midjourney. The results indicate that perceived usefulness, satisfaction, and ease of use significantly influence the continued usage intention of AIGC platforms by users. Factors such as expected confirmation, content quality, habit, enjoyment, and system quality also indirectly affect users’ intention to use these platforms. Valuable recommendations for designers include enhancing platform functionality, improving user experience and satisfaction, simplifying operation processes, ensuring content quality and system stability, and fostering user habits and enjoyment for continued usage. This study provides valuable insights for developers and young designer users of AIGC platforms, offering scientific suggestions for platform development to ensure their sustainability in the design industry.