“Micro-innovation” has become the key to sustainable business success in the context of ‘intelligent businesses'. Different from technological innovation, micro-innovation calls for employees to make use of their rich practical experience and expertise while doing the most common tasks in work. They are encouraged to put forward effective small improvements, inventions and ideas which are conducive to further practical operation. Job crafting reflects such a process in which employees spontaneously design their work, optimize work requirements and resources, and finish tasks successfully. In the past decade, scholars of organizational behaviors have studied job crafting and agreed that job crafting of employees is so significant that it will lead to continuous improvement of products (services) and further promote “micro-innovation”. Job crafting is thought to be a dynamic and continuous work process which fluctuates every day. In order to fully understand the formation process of job crafting in the real world, research scholars recently have even called for the research on job crafting in the daily level, which was ignored by previous research. Thus, we intend to focus on employees' daily job crafting, and explore the influencing factors and mechanisms of employees' daily job crafting behaviors. In addition, leaders' emotion display is regarded as an immediate response to the interaction between leaders and employees, and has a more direct impact on the employees' daily job crafting behavior. Thus, we believe that leaders ' emotion display has a much higher information value on employees ' daily behaviors. Although it has been agreed that leaders are the source of positive and negative emotion of subordinates in the workplace, negative emotion is stronger determinant of subordinates' perceptions of leaders than positive emotion. Some clues in the current relevant research literature can confirm this point of view. For example, Dasborough and his colleagues (2016) have found that subordinates could perceive and recall more negative emotional events that have occurred in the past in work situations in greater depth and detail. In addition, Wang and his colleagues (2018) have emphasized that the influence of leaders' negative emotion on their subordinates is more helpful to fully understand the motivational effect of emotion on leadership. Therefore, this study intends to open the black box and investigate the influence of leaders' negative emotion display on employees' daily job crafting. Based on the theory of Emotion as Information, this study used job daily method to examine the influence mechanism of leaders' negative emotion display on subordinates' daily job crafting. This study is based on 1389 daily data from 105 employees in a Biological Industry Co., Ltd. which is located in the North of China. Empirical research has applied multilevel structural equation model to examine the mediation effect of state self-esteem and epidemic motivation, latent moderated structural equations to examine the moderating effect of Leader-Member Exchange, and bootstrapping method to examine the moderated mediation effect of state self-esteem and epidemic motivation. The following conclusions were found: 1) Leaders' negative emotion display negatively predicted subordinates' state self-esteem; Subordinates' state self-esteem positively predicted daily job crafting; The relationship between leaders' negative emotions display and daily job crafting was mediated by subordinates ‘ state self-esteem; 2) Leaders’ negative emotion display positively predicted subordinates' epidemic motivation; Subordinates' epidemic motivation positively predicted job crafting; The relationship between leaders' negative emotions display and daily job crafting was mediated by subordinates ‘ epidemic motivation; 3) Leader-member exchange relationship moderated the relationship between leader’ s negative emotion display and subordinates ‘ state self-esteem / subordinates’ epidemic motivation. 4)The mediation effect of subordinates' state self-esteem / subordinates ' epidemic motivation is moderated by Leader-member exchange relationship. The above results not only respond to the confusion of previous research about whether Leader's negative emotion show negative effect on subordinates, but also help to take a more comprehensive look at the effect of leaders ' negative emotion display on employees' daily job crafting. In addition, the research results expand the practical research of Emotion as Information theory, clarify the influence mechanism of leaders ‘ negative emotion display on employees’ daily job crafting including affective reaction path and cognition-driven path, extend emotion display to the field of job crafting research, and further deepen the research about job crafting