From October 27 to 29, 2025, the "CSST-MCI Early Science Workshop" was held at the Shanghai Astronomy Museum of the Shanghai Astronomical Observatory, CAS. The event was co-organized by the Shanghai Astronomical Observatory of the Chinese Academy of Sciences and the CSST (China Space-Station Survey Telescope) Yangtze River Delta Regional Science Center. More than 50 representatives from various domestic research institutions and universities participated both online and in person.

With the continuous progress in the development of the China Space-Station Survey Telescope (CSST), scientific preparations for the Multi-Channel Imager (MCI), one of CSST’s five key payloads, have entered a critical phase. To coordinate follow-up efforts and enhance participants’ understanding of MCI, experts engaged in in-depth discussions and exchanges on topics including MCI’s observation modes and testing progress, early science proposals, and preliminary plans for in-orbit testing. Key scientific objectives were emphasized, such as eXtreme-Deep Field observations, galaxy cluster studies, MCI flux calibration, multi-populations of globular clusters, observations of AGN jets, and solar system object observations. Participants also conducted technical exchanges on observation strategies across different bands, instrument performance testing, and the selection of early science targets.

The successful convening of this workshop has laid an important foundation for the planning of MCI’s future in-orbit testing. Besides, collaborative exchanges will be further strengthened to ensure solid preparation for the scientific output of CSST, particularly that of MCI.