Children are one of the most vulnerable groups in society and their mental well-being can be negatively impacted in the aftermath of a disaster. Timely and effective interventions to reduce children’s psychological stress are important to protect their mental health and promote their healthy development. This is a case report of a case of post-traumatic stress disorder (PTSD) triggered by the earthquake of Jishi Mountain. Xiaofang (pseudonym) is a fourth grader with problems with traumatic reenactment experiences, avoidance, depression, and diminished volitional behavioral activity. We used film therapy to provide a professional intervention for our child patient Xiaofang, with six carefully selected films for six sessions of psychotherapy. During treatment, the psychological status of the child patient was comprehensively assessed using the Early Psychological Response Scale for the Accidentally Traumatized, the Hamilton Depression Rating Scale (HAMD), and the Hamilton Anxiety Rating Scale (HAMA) to monitor the efficacy of the treatment. At the end of treatment, Xiaofang demonstrated significant improvements in emotional reactions, depression, anxiety, and sleep quality. The application of the film demonstrates innovation and effectiveness in the field of dealing with childhood trauma and provides a new therapeutic avenue for psychological rehabilitation.