This study examined the mediating effects of loneliness in the relationship between social anxiety and life satisfaction. Four hundred and forty two left‐behind children in rural China, who completed the Social Anxiety Subscale, UCLA Loneliness Scale, and Satisfaction with Life Scale, participated in the study. Results indicated that compared with both parent migration children, the scores of life satisfaction in the mother‐only and father‐only migration children were strongly higher, but did not differ across genders and ages. Additionally, social anxiety and loneliness negative predicted life satisfaction. More important, the mediation analysis revealed a partial mediating effect of loneliness in the links from social anxiety to life satisfaction. These findings call on more attention from the government and related sectors of society, and propose that loneliness improvement program may have a preventive function for promoting the life satisfaction among left‐behind children.