【Abstract】 Objective Most studies indicate that the aviation accident frequently produce traumatic stress reactions in pilots. However, few study focus on the mental health state of pilots who exposed to an aviation accident when they service in the same army. To understand the characteristics and variation of the mental health state of pilots who exposed to an aviation accident, and provide key information for the pilots’ crisis intervention after the aviation accident, an investigation on the psychological factors was conducted in pilots who exposed to an aviation accident. Methods In this study, we investigated 78 pilots who in the unit exposed to the aviation accident by using the Symptom Checklist-90 (SCL-90) after the aviation accident for 3 days, 15 days, 2 months and 6 months, respectively. 72 pilots who in the same unit have not exposed to the aviation accident were regarded as the control. All the evaluation has conduced at the same time. Results The pilots had acute mental stress reactions after the aviation accident. At first, the main symptom of the pilots was somatization, later it was negative emotions such as anxiety and depression. The results also showed their suffering levels to be higher than those in control group and the total score, total mean score, positive items number, positive symptom score, ten factors and each factor score of SCL-90 in pilots who suffer the aviation accident were significantly higher than those in the control group after the aviation accident for 3 days and 15 days, respectively (P<0.05, P<0.01 or P<0.001). The mental health state of the pilots returned to normal after 6 months from the accident. Few of the pilots had a strong and lasting emotional reaction. Psychological health state of pilots exposed to the aviation accident is not optimistic immediately after the accident. They have higher score of interpersonal sensitivity, depression, anxiety, paranoid ideation than the control group after 2 months. All the factors have no significantly change between the pilots exposed to the aviation accident and the control group, except for the positive symptom score of the pilots exposed to the aviation accident was higher than the control group. 19 pilots’ total score of SCL-90 was higher than 160 (24.4%), while 12 pilots’ total score of SCL-90 was higher than 178 (15.4%). Conclusions The psychological crisis intervention should be implemented after an aviation accident. To help them better relieve psychological pressure and decrease psychological problems after the aviation accident, at the beginning, we should pay attention to the group intervention. Later, we should pay more attention to the pilots who have serious emotional reaction and track counseling to them to eliminate or reduce the mental health stress reaction after an aviation accident. To our knowledge, this is one of the first studies involving pilots who servicing in the army. The results clearly show the dynamic processes of change in mental health state of pilots after they exposed to an aviation accident.