The current study examined the psychological mechanism that underlies the relationship between parents’ response style and children’s subjective well-being and its boundary conditions, the mediating role of the parent–child relationship, and the moderating role of friendship quality. Using the Parents’ Responses to Children’s Performance Scale, the Buchanan Scale of Closeness to Parents, the Friendship Quality Questionnaire, and the Campbell Index of Well-being, our study investigated 686 pupils who were randomly selected from three public schools in central China. Employing Mplus 8.3 for pathway analysis, we found the following results: Failure-oriented responses negatively predict children’s subjective well-being (β = −0.16, p < 0.001), while success-oriented responses positively predict children’s subjective well-being (β = 0.13, p < 0.01). Both failure-oriented (ab = 0.18, SE = 0.03, 95% CI = [0.13, 0.25]) and success-oriented responses (ab = −0.10, SE = 0.02, 95% CI = [−0.14, −0.06]) predict children’s subjective well-being through the mediating effect of the parent–child relationship. Friendship quality has a moderating effect on the mediating path (β = −0.09, p < 0.05), such that when friendship quality is lower, the parent–child relationship has a higher mediating effect between the parents’ responses and children’s subjective well-being. This study offers empirical evidence that parents’ responses to children’s performance significantly contribute to children’s subjective well-being. Moreover, it offers actionable insights for enhancing children’s subjective well-being. The enhancement could be achieved by fostering positive parent–child relationships and enhancing the quality of children’s friendships, thereby positively impacting their well-being.