Relative poverty represents a major obstacle to China's rural revitalization efforts and necessitates enhanced policy support. This study aims to investigate the impact of household distributed photovoltaic (HDPV) on relative poverty conditions. Based on 337 questionnaire data from Jiujiang City, Jiangxi Province in 2022, we construct a multidimensional relative poverty index using the Alkire-Foster method to assess the level of relative poverty. We employ fixed-effects models and mediation models to evaluate the effectiveness of HDPV in alleviating relative poverty. The results indicate that HDPV reduce the multidimensional relative poverty level of rural residents by approximately 0.058, demonstrating that installing HDPV can significantly alleviate multidimensional relative poverty. This effect is primarily achieved through increased investment in children's education. Additionally, we find that the alleviation effect varies by income level, with lower-income households experiencing greater improvements compared to higher-income households. Specifically, HDPV reduce the poverty level of the low-income group by approximately 0.0969, while the high-income group saw a reduction of about 0.0313. The findings of this study enrich the research on relative poverty in China by revealing the poverty-alleviating attributes of HDPV. It provides support for the development of renewable energy and regional development policies and has practical significance for advancing photovoltaic building integration.