This study chose major Chinese cities and used the creative model of Smart Low-carbon Strength Quotient (SLSQ) to investigate the level and state of urban smart low-carbon development. The results show that: (1) three main categories of smart low-carbon cities are found; namely, leaders with high SLSQ, steady ones with average SLSQ and lagging ones with low SLSQ; (2) the SLSQ level shows a spatial change trend of diminishing from the southeast to the northwest and differing within regions; (3) the SLSQ level indicates an urban scale change trend of decreasing from the big to the small and differing within each scale; (4) the SLSQ level suggests an administrative hierarchy change trend of descending from the high to the low and differing within each class; (5) based on the SLSQ, three dynamic patterns were identified: leading mode, steady mode and preparing mode, among which the steady mode accounts for the vast majority of smart low-carbon development in major Chinese cities.