Emotion regulation can be achieved through a number of processes. Implicit/automatic emotional regulation is a widely used form of emotion regulation. Studies have shown that implicit emotion regulation strategies such as reappraisal can reduce the intensity of negative experience and brain activity sensitive to emotional salience. However, the time course of implicit reappraisal-related neural modulation remains unclear. It is unknown whether implicit reappraisal conditions before picture onset elicit attentional orienting towards and anticipation of impending stimuli. To fill this gap in the field, we examined the electrocortical response to unpleasant pictures during the implicit reappraisal condition, the modulation’s time processing, and the physiological changes elicited by instruction cues. In this study, a total of 20 participants were recruited. The implicit reappraisal strategy by giving them precedent descriptions was used to attenuate the emotional impact of unpleasant pictures. Event-related brain potentials (ERPs) were recorded while participants passively viewed neutral, unpleasant, and reappraised the unpleasant pictures. Late positive potential (LPP) is a positive-going ERP that begins parietally 200 ms following stimulus onset. The LPP is related to attentional processing to stimuli with motivational significance, which is larger following the presentation of emotional compared to neutral visual stimuli. Stimuli-preceding negativity (SPN) is a negative slow-wave that grows with anticipation of an impending feedback stimulus. The SPN is believed to reflect attentional orienting towards and anticipation of impending stimuli. We focus on these two ERP components to examine the differences between passively viewed neutral pictures, passively viewed unpleasant pictures, and implicitly reappraised before the view of the unpleasant pictures. The main goal of the present study was to investigate whether an “implicit reappraisal strategy” would modulate the LPP and SPN associated with unpleasant picture viewing. The result shows that the LPP was enhanced for unpleasant pictures in the passive viewing block. The implicit reappraisal resulted in a reliably reduced LPP—a protracted modulation that began 500 ms after stimulus onset, continuing the process of the whole picture presented. We also sought to ensure that there were no observable differences between the passively viewed and implicit reappraisal conditions before picture onset by analyzing ERPs during the presentation of the instruction cue. In particular, we examined the frontally maximal stimulus-preceding negativity ERP component during the cueing window (the 2000 ms window in which subjects saw a cue to either View, Watch, or Descriptions). The result also showed that the implicit reappraisal instruction cue before picture onset do elicit attentional orienting towards and anticipation of impending stimuli. The present study supported conclusions from other papers that implicit reappraisal can reduce the emotional response to unpleasant stimuli. The results of this study help people understand the time-processing process of implicit reappraisal strategies, and have important guiding significance for the clinical intervention of implicit emotion regulation. Since emotional regulation deficits are associated with mental and personality disorders, research on implicit emotion regulation is essential for clinical subjects (such as anxious individuals) who cannot reduce negative emotions and frequently use ineffective emotion regulation strategies. Therefore, future research should focus more on investigating the difference in implicit reappraisal strategies between healthy subjects and clinical subjects.