Lawful supervision of mobile terminals is an important means of national security sectors to guarantee mobile network security.And access of identity of mobile terminal is basis for supervision.Based on description of the main identities of mobile terminal and the research status of supervision system,this paper proposes a design scheme of multiformat mobile terminal identity detection system,which can be applied to dual-arfcn GSM network and WCDMA network,clarifies its technical principle and implementation processes,and presents a technical solution for system optimization.The multiformat identity detection scheme is verified through system test.