<p>Decision-making is a complex cognitive process, in which emotion is one of the most important factors. But insights into the influence of emotion on decision-making are scarce, especially the underlying mechanism of the brain. To reveal the brain’s underlying mechanisms of the influence of emotion on decision-making, an experiment involving emotion elicitation and decision-making tasks was designed. Electroencephalography (EEG), behavioral, and subjective data were collected and conducted. We constructed time-varying weighted directed networks by phase slope index (PSI) in four frequency bands and calculated graph theory metrics. Firstly, the period that the brain processes information most efficiently is 100–300 ms after the appearance of the decision-making task. Secondly, by analyzing the temporal-spatial domains of EEG, the significant differences in global efficiency (GE) and local efficiency (LE) were found among three different emotion groups in the alpha band in the low-difficulty task during 100–300 ms. Thirdly, most activation regions of different emotions were similar and concentrated in the parietal, and occipital lobes but there were still slight differences that were more likely to be found in the prefrontal and left temporal lobes. Graph theory metrics in the decision-making process changed dynamically in the temporal domain and graph theory metrics of different emotions were different.</p>