The affect heuristic refers to that people consult the positive and negative feelings consciously or unconsciously associated with the mental representations of the task in the process of making a judgment or decision. In the current paper, we first introduced the definition and importance of affect heuristic. Then we reviewed studies on the affect heuristic, Summarizes its psychological mechanisms and some factors. At the end of the paper, we gave several suggestions regarding to the directions for future research. Just as imaginability, memorability, and similarity serve as cues for probability judgments (e.g., the availability and representativeness heuristics), affect may serve as a cue for many important judgments. Affect may also serve as a cue for many important judgments and decisions (Kahneman, 2003). Affective responses tend to occur rapidly and automatically. As such, using an overall, readily available affective impression can be quicker and easier—and thus sometimes more efficient—than weighing the pros and cons or retrieving relevant examples from memory, especially when the required judgment or decision is complex or cognitive resources are limited. Researchers have noted that the affect heuristic is widespread in consuming decisions, environment protections, financial investments and justice field. Psychological mechanisms of affect heuristic mainly include affect heuristic model (AHM) and dual-process theory. According to AHM, individual’cognition for risks and gains is always associated with the affect evaluation when judging risks and gains of behaviors. That is, when certain behaviors are perceived “like”, it may be regarded as low-risk and high-income. It may be considered as high-risk and low-income when certain behaviors are perceived “dislike”. Thus AHM shows that in process of cognition for risk behaviors, affect evaluation comes first, and judgment of risks and gains follows. Dual-process theory argues that there are two systems to work in processing information, experiential system and rational system. Experiential system mainly rely on intuitions which need no or less psychological resources, resulting in a faster pace, however, rational system is dependent on reasoning which employ more psychological resources, resulting in a slower pace. Since affect play a direct role in processing information, our brains tend to base a quick determination on affect and experience, which means affect heuristic. Past researches have shown affect heuristic shaped by other factors as well, like individual experience, time pressure, evaluability, counting ability and so forth. There is considerable evidence that judgments and decisions are often based on an affect heuristic. However, we know surprisingly little about why people are more likely to rely on this heuristic (Paulus & Yu, 2012). Future research can employ decision-making task on populations of different evolutionary degree from perspective of evolution and analyze the extent to which the emotion involves in to explore the process of affect heuristic, thus deeply understanding the generation mechanism of affect heuristic. In addition, we can also deeply explore the correlation between areas such as amygdala, hippocampus, ACC, ventromedial striatum and affect heuristic as well as further extending the application of affect heuristic in individual and group.