Under the background of constructing a strong financial country, China’s banking industry is undergoing continuous reform and adjustment. The policy banks in China have made remarkable contributions to the construction of a socialist market economy, and their operational efficiency is closely linked to the stability of the financial environment and the development of the national economy. This study employs data envelopment analysis to examine the performance of China’s policy banks from 2012 to 2022, evaluating their comprehensive technical efficiency, pure technical efficiency, and scale efficiency. The findings indicate that while China Development Bank demonstrates good operational efficiency, with only one year failing to reach an effective state; Export-Import Bank of China and Agricultural Development Bank of China initially exhibited fluctuating trends but gradually stabilized in later stages. Based on these results, relevant suggestions are put forward to improve the operational efficiency of policy banks.