Individuals usually present highly stable differences in household energy conservation intentions. Personality traits are a possible explanation for such differences. However, the mechanism through which personality traits affect household energy conservation intentions is still unclear. This research aims to explore the roles of personality traits in household energy conservation intentions by connecting the Big Five personality traits with household energy conservation intention through the Theory of Planned Behavior (TPB). The study employs data from a survey in Xi'an, China, with a valid sample size of 279 households. The analysis results indicate that, except for Extraversion, the other four personality traits affect household energy conservation intentions through different mechanisms. Agreeableness and Openness show positive correlations with all three TPB predictors. Conscientiousness also presents a positive correlation with perceived behavioral control, while Neuroticism only presents a negative relationship with attitude. This study combines personality traits with TPB to investigate household energy conservation intentions. The results provide a shred of empirical evidence on the relationships between personality traits and pro-environmental behaviors in northwest China. The findings of this study would contribute to eco-friendly policy-making for sustainable community development.