Improving green total-factor productivity (GTFP) in the power industry is crucial for achieving China's clean and low-carbon transition and sustainable economic growth. Green technological innovation (GTI) is a key factor driving carbon emissions reduction and improving economic efficiency in the power industry. Therefore, this study utilizes data from 30 provinces in China covering the period 2005-2021 and employs a Difference-in-Difference (DID) model to investigate the impact of the carbon trading pilot policy (CTPP) on GTFP in the power industry from the perspective of GTI. The results indicate the following: First, CTPP significantly enhances GTFP in the pilot regions of the power industry. Second, GTI plays a positive mediating role in the relationship between CTPP and GTFP in the power industry, validating the existence of Porter effect in China's power industry carbon emission trading system. Third, there are heterogeneities in the policy effects across the pilot regions, with Beijing and Guangdong achieving outstanding results in improving GTFP compared to other carbon trading pilots. Finally, relevant policy recommendations are provided for carbon market development and improving GTFP in the power industry.