Computer forensics is an important part of the computer crime investigation. So a Forensics system aimed to Foxmail data analysis and investigation is proposed in this paper. The system can index the email data based on Lucene technology and the MMSeg participle algorithm, and provides the full text retrieval of the email content function. Subsequently, a visual communication graph would be generated according to the retrieval results. Based on the communication graph, an algorithm on graphic structure analysis is proposed, and by means of centrality and minimum traffic filtering method, multilevel analysis is carried out on the graph, which can detect the possible suspicious personnel and their relationships and provide strong support for the computer crime investigation.