A total of 187 flood victims from Wuhu, a Chinese city affected most severely by a flood during July 2016, were selected to complete self-report measures of traumatic exposure, feelings of safety, fear, posttraumatic negative cognition, and posttraumatic stress disorder. The results found that traumatic exposure could directly predict posttraumatic stress disorder. Besides, traumatic exposure had indirect prediction on posttraumatic stress disorder through three ways, including a one-step path of negative self-cognition, a two-step path from feelings of safety to fear, and a three-step path from feelings of safety to negative self-cognition via fear. Implications and future directions are correspondingly discussed.