The previous moral injury theory implied the premise of taking individual as the research object, while there were few studies on collective moral injury. Collective moral injury is defined as a series of consequences of violating widely accepted moral beliefs rather than simply adding up symptoms of injured individuals within a group. From the America "Floyd Case", this paper analyzed the functional elements and generating mechanism of collective moral injury, that was, the diversification of trauma sources events could appear alone or interweave, collective moral resilience showed the characteristics of social integrity and time accumulation, the interaction between collective trauma sources and collective moral resilience determined whether collective moral injury occurs. As the We-Media become popular, collective feature of moral injury is more evident, which presents two new features that the Internet platform becomes a hub for trauma events and the information Internet recorded consolidates collective moral resilience. To deal with collective moral injury, it was needed to respond to social concerns and guidance moral public opinion, respect the original endogenous order and inherit the traditional culture, satisfy reasonable moral needs and enlighten moral sense of people as well.

Moral emotion is a kind of psychological activity that generated when dealing with realistic moral relationship or analyzing human behaviors, expressed as emotional emotions of love and hatred. From the perspective of moral injury research, on the one hand, moral emotion expresses as emotional collapse, which reflects the huge gap between reality and moral cognition, and deviates from values; on the other hand, it shows the typical symptoms of moral injury, such as shame, guilt, anger, apathy and so on. Based on this, the therapy of moral injury should start from solving the ethical conflict of moral injury, and carry out the healing process of "ethical and moral cognitive education, enlightening the thinking of core value issues, encouraging and guiding independent moral practice" in stages according to the different levels of individual moral emotion. As a result, moral emotion can be rational enough to promote healing moral injury.