Abstract: To address the issues of insufficient source-load coordination and the limited constraint capacity of fixed carbon price mechanisms in rural islanded integrated energy systems (RIIES), this paper proposes a low-carbon optimal scheduling model considering source-load collaborative response and a tiered carbon trading mechanism, with the objective of minimizing the total daily operating cost. Case study results demonstrate that under their combined effect, the system"s wind and solar power accommodation rate reaches 100%. Furthermore, compared to the fixed carbon price mechanism, carbon emissions and carbon trading costs are reduced by 21.20% and 13.39%, respectively, effectively achieving the low-carbon and economic operation of the RIIES.