Aiming at the main challenges facing cloud forensics,cloud characteristics were analyzed and a cloud forensic model was proposed.In the model,the deployment of persistent forensic readiness service,multi-round identification strategy based on “iteration” and multi-level evidence location method for distributed file system,“data isolation” and “on-demand collection” strategies,and the establishment of comprehensive evidence analysis platform based on cloud resources were presented.Finally,the validity of the model was analyzed combining the forensic scene in the cloud environment.