Abstract: Advancing the localization of sustainable development assessment is significant both globally and locally. By aligning the goals of the United Nations’ Sustainable Development Agenda with the tasks of Chinese-style Modernization, this study proposes an evaluation index system that incorporates peak and net-zero carbon emissions and common prosperity into sustainable development assessment. It encompasses five key dimensions of sustainability: high-quality economic growth, social well-being improvement, equitable sharing of prosperity, green and low-carbon transition, and environmental governance, including 48 specific indicators. Using this evaluation index system, we evaluate the progress of sustainable development in 31 Chinese provinces from 2013 to 2022, with a particular focus on the spatial correlations and dimensional coupling coordination of provincial sustainability, examine the impacts of efforts towards peak and net-zero emissions and common prosperity on provincial sustainability, validate the scientific rigor of our evaluation index system, and discuss the limitations of this study and potential solutions. The results show that: (1) Provincial sustainability has continued to improve by 1.50% annually on average, exhibiting a distinct spatial gradient from southeast to northwest China; (2) The spatial positive correlation of provincial sustainability has gradually strengthened, accompanied by an intensification of spatial polarization. This polarization is characterized by increasing number of high-high and low-low clusters concentrated within the southeast and northwest of the Hu Line, respectively; (3) Provincial performance across all the five dimensions has improved, with the dimensions of high-quality economic growth, social well-being improvement, and equitable sharing of prosperity experience an east-to-west spatial gradient, while the dimensions of green and low-carbon transition and environmental governance follow a south-to-north spatial gradient; (4) Despite improvements in the coupling coordination among the five dimensions, it remains at a relatively low level in 22 provinces, especially in the northwestern regions, where disparities between environmental governance and high-quality economic growth are particularly pronounced; and (5) Efforts towards peak and net-zero emissions and common prosperity both have affected the provincial sustainability, particularly the former through trade-offs that result in a decline in the sustainable development rankings of ten provinces, with an average drop of four positions. By integrating peak and net-zero carbon emissions and common prosperity to improve a localized assessment methodology for sustainable development in the context of Chinese-style modernization, our findings are more targeted, interactive, flexible and balanced and therefore offering valuable insights into the spatio-temporal variations in sustainable development at the provincial level.