<p>Children’s affect plays a crucial role in their mental health, academic performance, and social adjustment. However, previous studies on the relationship between life events and affect have primarily focused on adolescents or adults, leaving unclear how daily life events influence children’s affect in real school settings. This study used a 10-day daily diary design to examine the momentary relationships between life events and affect among 193 Chinese elementary school students (41.45% girls; <i>M</i>_age = 11.61, <i>SD</i> = 1.17). Each day, students reported their positive and negative life events and their affective states, while their achievement goals (mastery, performance-approach, and performance-avoidance) and affective traits were assessed as between-person variables. Multilevel models were constructed to examine both the same-day and the next-day associations. Results of moderation analyses revealed that mastery and performance-approach goals significantly attenuated the negative relationship between daily negative events and same-day energetic affect (all corrected <i>ps</i> &lt; 0.05, BH-FDR-adjusted). Additionally, performance-avoidance goals moderated the associations of both positive events with same-day worry and negative events with energetic affect (all corrected <i>ps</i> &lt; 0.05). Simple slope analyses indicated that these protective effects were primarily evident at higher levels of the respective achievement goals. No significant moderation effects were found for next-day affective outcomes. These findings suggest that school-based efforts to support students’ emotions may benefit from focusing on same-day, context-specific supports and considering goal-orientation differences.</p>