Objective To investigate the suicide related factors of the teenagers after trauma and further discuss the prevalence and related factors of suicide idea plan and behavior. Methods Using the general information questionnaire and the Youth Risk Behavior Survey (YRBS) to investigate the primary and secondary students in the nine worst-hit areas in Wenchuan earthquake of 2008, with cluster random sampling and the class as a sampling unit, to extract random 110 primary and middle schools and gather their general information, disaster-related cases and scores of suicide in YRBS. According to the different types of data, we used descriptive statistics,t test,Chi square test and Logistic regression analysis and respectively use single factor analysis and multivariate logistic regression analysis for suicide idea, plan and behavior. Results A total of 7 833 questionnaires were sent out and a total of 7 521 questionnaires were collected and the recovery rate was 96. 02%. Among them, there were 6 875 valid questionnaires (91.41%) and 636 invalid questionnaires. According to the investigation, the prevalence of the primary and secondary students which had seriously considered suicide was 6. 90%, which had a plan to commit suicide was 4.00% and which tried to take over the action of suicide was 2.70%. With general information for the independent variable, logistic regression analysis showed that whether there had seriously considered suicide as the dependent variable: age (OR=1.178, 95%CI 1.098 to 1.178) and changed in family structure after the earthquake (OR=1.360, 95%CI 1.360 to 1.085) were risk factors for post disaster the teenagers with suicide idea; whether there had been plan to commit suicide as the dependent variable: age (OR=1.099, 95%CI 1.050 to 1.150), the history of being buried in ruin (OR=2.155, 95%CI to 1.104 to 4.205) and changed in family structure after the earthquake (OR=1.495, 95%CI 1.128 to 1.981) were risk factors for post disaster the teenagers with suicide plan; whether took over the action of suicide as the dependent variable: male (OR=1.513, 95%CI 1.122 to 2.039) and changed in family structure after the earthquake (OR=1.555, 95%CI 1.112 to 2.175) were risk factors for post disaster the teenagers with suicide behavior. Conclusion Age and changed in family structure after the earthquake were the risk factors for suicide idea and age was positively correlated with suicidal idea. Age, had the history of being buried in ruin and changed in family structure after the earthquake were the risk factors for suicide plan and age was positively associated with suicide plan. Male and changed in family structure after the earthquake were the risk factors for suicide behavior. Among them, changed in family structure after the earthquake was the common risk factor. So there should be targeted psychological assessment and psychological rehabilitation intervention to avoid the risk of suicide among the teenagers after the disaster.