The present invention relates to a system and method for device management security, and more particularly to a system and method for device management security of a trap management object (Trap MO), which can prevent a non-authorized device management server from indirectly controlling device management of a mobile terminal through use of the Trap MO defined in Open Mobile Alliance Device Management (OMA DM). To this end, when a DM client receives a request to register a notification target MO as a recipient node registration from a DM server, the DM client determines if the DM server has authority for both addition and execution and allows only an authorized DM server to register a recipient node in the Trap MO, so that only a DM server having authority for execution of an MO can execute the MO and control the device management of a mobile terminal. Accordingly, it is possible to enhance device management security of the mobile terminal against non-authorized DM servers.