Against the backdrop of global climate change and China’s dual-carbon goals, monitoring and analyzing the carbon emissions of the tourism industry is of great significance. This study constructs a measurement system for tourism carbon emissions based on CO2 emission coefficients and applies the Generalized Divisia Index Method (GDIM) to systematically decompose the influencing factors. Using data from 2011 to 2022, we examine the emissions of tourism transportation, tourism accommodation, and tourism catering. The results show that tourism carbon emissions increased rapidly before 2019, declined during the COVID-19 pandemic. Tourism transportation remains the dominant source, while tourism catering has become the fastest-growing sector, surpassing tourism accommodation since 2016. Tourism economic expansion and rising consumption are identified as the main drivers of emission growth, whereas improvements in carbon intensity play a significant mitigating role. This study provides a systematic understanding of the emission dynamics of China’s tourism industry and offers practical insights for achieving low-carbon development.