Establishing a scientific and reasonable comprehensive evaluation index system for pollution reduction and carbon reduction is an important basis for supporting the implementation of the plan, promoting the continuous optimization of related tasks and achieving practical results. In this paper, a comprehensive evaluation index system of pollution reduction and carbon reduction in Tianjin is established, which considers the factors of environment, low carbon, green and coordinated development, and is applied in practice with the historical data of Tianjin. The conclusions are as follows. The total pollution reduction and carbon reduction index of Tianjin is growing rapidly, with an average annual growth rate of 26% from 2015 to 2023. Low-carbon energy transformation is the main driving force, and the contribution of transportation transformation and upgrading to pollution reduction and carbon reduction is obviously enhanced.