With the continual advanvement of Information Construction in Public Security, it is important to boost the direction and the validity of police work and improve the level of Information Construction, if interested information can be mined from the large amount of historical data. Based on an earlier study, this paper improves the GA-FCM from the population selection and the mutation operator. Finally, the improved algorithm is also applied to the traffic accident data mining. The results have shown that the algorihm contributes significantly in preventing traffic accident and improving the traffic situation.