Abstract Low-carbon energy transition is conducive to saving energy and reducing emissions, and its impact on energy poverty warrants intensive attention. By employing a balanced panel dataset of China's 30 provinces for the period 2004–2017, we examine the causal relationship between low-carbon energy transition and energy poverty by using a novel nonparametric panel causality-in-quantiles (PCIQ) method. Also, the internal impact mechanism between low-carbon energy transition and energy poverty is analyzed. The primary findings of our study imply that low-carbon energy transition shows significant bidirectional causality with energy poverty alleviation. And the low-carbon energy transition can stimulate energy poverty alleviation by affecting poverty in the availability of energy services, the cleanness of energy consumption, the integrity of energy management, and energy affordability and efficiency. Our findings provide an important reference for the government to formulate relevant policies that promote the alleviation of energy poverty.