People differ in adult attachment style perceive and regulate their social relationships and emotions in the different ways. Previous researches have investigated the efficiency and preference of emotion regulation strategies among different attachment styles and found that the secure attachment individuals tend to reappraise the context and reinterpret events in a mildly way while the avoidant individuals prefer to deactivate the distressed experience and suppress emotional expression. However, empirical evidences were still lacked when exploring the temporal dynamics of the neural processes. The current study tends to fill this research gap by using event-related potentials(ERP) to investigate how avoidant and secure attachment individuals differ in their two emotion regulation strategies: cognitive reappraisal and expression suppression, in lovers intimate scenarios. Forty-three participants(twenty-two avoidant and twenty-one secure attachment individuals), ages of 18–25 years, participated in the study. The experiment consisted of two sessions. In the first session, participants were instructed to freely view(VIEW) and to respond naturally to the content without trying to alter the upcoming emotions. In the second session, participants were instructed to regulate their emotions either in a reappraisal way or in a suppression way. Results showed that:(1)secure attachment individuals reported significantly higher level of pleasure than the avoidant individuals in response to the intimate pictures;(2) secure individuals reported significantly higher level of valence and arousal scores than the avoidant individuals in the emotion regulation condition. ERP analysis further indicated that the mean amplitude of the LPP in response to the intimate pictures in the secure individuals when adopting the cognitive reappraisal strategy was significantly lower thanwhen they in the free-viewing condition in five time windows. However, when using expression suppression strategy, secure individuals showed a significantly reduced LPP amplitude in 300–500, 500–700 ms time windows, compared with the free watching conditions, and showed increased LPP amplitude in 900–1100 ms and 1100–1300 ms time windows. For avoidant individuals, which they used expression suppression strategy, the pictures evoked a significant lower LPP amplitude compared to free-viewing condition in the five time windows. However, there was no significant differences when they used reappraisal strategy compared to spontaneous watching. In sum, there were significant differences both in the subjective emotional measures and electrophysiological responses in response to the lover’s intimacy pictures between the avoidant and secure attachment individuals which they used either the cognitive reappraisal or the expression suppression to regulate their positive emotions. At an early phase of positive emotion regulation, secure individuals applied cognitive reappraisal strategy to regulate emotions efficiently or sustainably, while the avoidant individuals used expression suppression strategy. This study enriched the theoretical relationship between the different emotion regulation strategies and attachment styles, and broadens the research width of emotion regulation and attachment, which can further provided theoretical basis for future researches focusing on the emotion regulation.