The study was intended to provide a direction for coaching to prevent toxic leadership from field unit leaders and promote self-development of leadership. To this end, the concept and sub-factorial characteristics of toxic leadership were divided into behavioral and character characteristics through a literature survey, and the cause of toxic characteristics of leaders was examined from a psychological perspective. The survey of field troops then compared the status of the leader's toxic leadership that his subordinates feel subjective with the leadership score. The results showed that the leader's toxic behavior can be attributed to psychological rigidity, depression, anxiety, and low self-esteem, and that even for leaders with outstanding leadership, toxic behavior may appear. Based on these results, the discussion points of future military coaching studies were presented to prevent toxic leadership in the military.