While some studies have examined the influence of bilingual language experience on executive control, few studies have looked at both bilingual experience and socioeconomic status (SES) together to see whether one, both, or an interaction exists when examining the executive control processing during a nonverbal conflict resolution task. To address this issue, the current study took advantage of event-related brain potentials (ERPs) as a group of bilinguals performed a nonverbal Stroop task for examining the influence of L2 proficiency and language switching frequency (bilingual language experience) on executive control. The electrophysiological results showed that L2 proficiency influenced the nonverbal Stroop task across congruency conditions and that the L2 proficiency effect was independent of individual’s socioeconomic status. However, no evidence for language switching frequency effects on executive control were observed. These findings provided new electrophysiological evidence for the relationship between bilingual language experience and executive control, indicating the important role of L2 proficiency in executive control performance in bilinguals.