AbstractThe low‐carbon transition involves achieving the coordinated development between economic development and carbon reduction. This paper utilises an integrated decomposition and econometric framework to reveal the influence mechanism and convergence evolution of carbon emission intensity (CEI) across 29 OECD countries in the period 1992–2018. The country‐level low‐carbon transition efforts are then investigated. The results imply that: (1) The reduction in CEI is primarily attributed to the changes in economic development and energy intensity. The carbon emission coefficient effect also negatively influences CEI. The impact of energy consumption per capita, however, is negligible. (2) According to econometric analysis, energy intensity, energy mix, carbon emissions per capita and energy use per capita have positive impacts on CEI. Specially, GDP per capita shows an inverted U‐shaped curve relationship with CEI. (3) There is evidence of convergence in CEI across developed countries. Energy intensity plays a crucial role in accelerating the CEI convergence process, implying a half‐life of 3 years. (4) Fifteen European countries have made strong low‐carbon transition efforts among all countries. Denmark has made the largest efforts, South Korea the least. This study provides important implications for low‐carbon economy transition.