So this study,in the presence of flammable liquid fires burn marks a certain judgement guidance.

When we check the criminal locale, we should pay attention to the material evidence aswell as the suspects thought.

The material trace on the spot of crime hides corresponding trace of psychology,which is the combined result of psychological activity and behavior of the person committing the crime,the full embodiment of inherent logic of development and connection and also a objective existence of reality.

There exist material trace with general and stable traits and psychological trace with subjective, recognizable, abstract, indirect and disguised features on the crime scene.

Mentally imprint is reflected out indirectly through the material trace in crime scene.

Its characteristics are revealed in the suspect s behavior pattern, personal character and trace evidence of a crime scene.

The paper,from the point of view of analyzing explosion spot,guided ty technical theory on evidence,discusses the characteristic of trace evidence in explosion spot and comprehensive application of them in investigation.

Simulation is based on the scene investigation of real cases,combined with what they have learned the characteristics of professional courses,emphasizes the students’ability of investigating,analyzing and using various types of trace evidence,and finally in the form of small groups to complete a full trace of evidence inquisition identification and inspection files.