The discovery of mirror neurons in the 1990s has led to much excitement in the cognitive neuroscience. Mirror neurons have received a great deal of attention from specialists both in the scientific field and public media. More and more abilities have been attributed to these neurons, they are even hailed as “do for psychology what DNA did for biology”. And a series of studies related to them have given rise to “a revolution in understanding social behavior”. Mirror neuron have been ascribed a wide variety of functions, such as action understanding, imitation, empathy, theory of mind, language evolution, telepathy, self-awareness, substance use disorders, etc. Mirror neurons are viewed as “holy grail” of cognitive science. Although, mirror neurons are widely assumed to play a key role in social cognition, florescence of often-aggressive debates have also arisen in this field. This review shows that current data about mirror neurons are very mixed and those studies using weakly localised measures to examine the functions of mirror neuron (system) are hard to interpret. Firstly, some theorists misuse and abuse the operational definition of mirror neurons. Mirror neurons are a class of visuomotor neurons activated by both the execution and the passive observation of object-related actions. Cells having this property were only found in macaques within the premotor cortex (area F5), and in the rostral part of the inferior parietal cortex (PF). Secondly, the idea that mirror neurons are existing in human being remains controversial, Though the human homolog of inferior frontal gyrus (IFG) and inferior parietal lobule (IPL) can be seen as classic human mirror neuron system. We systematically review the empirical foundations of mirror neuron researches, it turns out that unless someone can manage to evade all of the ethical, technical, and procedural limitations imposed on human brain research, no complementary research can be carried out to demonstrate the existence of mirror neurons in human brain convincingly with microelectrodes or any other technique operations at the neuronal level. Last but not the least, claiming the mirror mechanism plays a crucial role in understanding the behavior of others does not imply that there are no other mechanisms involved in action understanding. Some of these mechanisms based on the social brain are basic and not be ignored, relying on the association between a given stimulus and its corresponding effect. Based on this, the mirror neuron (system) and its mirror mechanisms neither can be used to account for empathy, imitation and mindreading, nor can explain other social cognition phenomena. It’s an outdated ideology as modularity of mind. The future study for mirror neurons must attempt to answer the following questions. (1) How can an agent make a distinction between the intention of self-action and those of others? And how can mirror neuron (system) and other social brains cooperate in this processing? (2) How can an agent make an understanding outcome prediction of action, it isn’t depends not at all on the action itself, but on the context which action embedded, so inferential reasoning or embodied simulation carry out processing?