To study the perception of threat through enironment-picture task, 30 children with autism spectrum disorders(ASD) participated in the exprimental research, and their eye movements were recorded with a Tobii X120 eyetracher. The results indicated that (1)children with ASD showed a perceptive advantage for threating targets, which was affected by the types of stimulating sources and the size of matrix in a certain degree, especially in the small size matrix of environment-picture task. (2)Children with ASD showed a fixed-attention to picture displaying an all-threating negative environment. Compared to other environmental picture, children with ASD were took more fixation duration time in the all-threating negative enviroment picture in the small size matirix task. (3)Eye-tracker technology can be effectively applied to the study of perception of threat in children with ASD, which could be provided more important reference material to the further research.