An encryption method, characterized in that the method comprises: sending, by a terminal or by a terminal used currently by a user, an encryption request message to a Device Management, DM, server, and receiving, by the terminal, an encryption instruction from the DM server; performing, by the terminal, an encryption operation for data of the terminal according to information of an encryption sub-node of an Encrypt And Decrypt Management Object, EADMO, node of a local DM tree when receiving the encryption instruction sent from the DM server; wherein the EADMO node is a node added to the DM tree of the terminal; reporting to the DM server, by the terminal, encrypted data state information generated after the encryption succeeds; updating, by the terminal according to an updating instruction sent from the DM server, information of a Store Uniform Resource Locator, URL, sub-node of the EADMO node of the DM tree into a URL for the DM server to locally store the encrypted data state information; wherein the encrypted data state information includes following information of encrypted data: an encryption mode, an encryption keyword and an encryption level; wherein the encryption sub-node of the EADMO node of the local DM tree comprises: an encryption mode sub-node, an encryption key words sub-node and an encryption level sub-node; wherein information stored by the encryption mode sub-node is a set encryption mode, including encryption by a file name and/or encryption by a file suffix name; information stored by the encryption key words sub-node is a set encrypted keyword, including a file name keyword and a keyword of a file suffix name, and the file name is a file name without a file suffix name; information stored by the encryption level sub-node is a set encryption level; different encryption levels are set according to different complexities of encryption algorithms, and an encryption level is positively correlated to the complexity of an encryption algorithm; wherein the step of performing an encryption operation for data of the terminal according to information of an encryption sub-node of an EADMO node of a local DM tree when receiving the encryption instruction sent from the DM server comprises: when the terminal receives the encryption instruction, which is an instruction for executing a preset instruction string in the encryption sub-node of the EADMO node of the DM tree, sent from the DM server, performing, the encryption operation for data of the terminal according to information stored by the encryption mode, the encryption key words and the encryption level sub-nodes in the encryption sub-node of the EADMO node of the DM tree to generate the encrypted data state information. sending, by a terminal or by a terminal used currently by a user, an encryption request message to a Device Management, DM, server, and receiving, by the terminal, an encryption instruction from the DM server; performing, by the terminal, an encryption operation for data of the terminal according to information of an encryption sub-node of an Encrypt And Decrypt Management Object, EADMO, node of a local DM tree when receiving the encryption instruction sent from the DM server; wherein the EADMO node is a node added to the DM tree of the terminal; reporting to the DM server, by the terminal, encrypted data state information generated after the encryption succeeds; updating, by the terminal according to an updating instruction sent from the DM server, information of a Store Uniform Resource Locator, URL, sub-node of the EADMO node of the DM tree into a URL for the DM server to locally store the encrypted data state information; wherein the encrypted data state information includes following information of encrypted data: an encryption mode, an encryption keyword and an encryption level; wherein the encryption sub-node of the EADMO node of the local DM tree comprises: an encryption mode sub-node, an encryption key words sub-node and an encryption level sub-node; wherein information stored by the encryption mode sub-node is a set encryption mode, including encryption by a file name and/or encryption by a file suffix name; information stored by the encryption key words sub-node is a set encrypted keyword, including a file name keyword and a keyword of a file suffix name, and the file name is a file name without a file suffix name; information stored by the encryption level sub-node is a set encryption level; different encryption levels are set according to different complexities of encryption algorithms, and an encryption level is positively correlated to the complexity of an encryption algorithm; wherein the step of performing an encryption operation for data of the terminal according to information of an encryption sub-node of an EADMO node of a local DM tree when receiving the encryption instruction sent from the DM server comprises: when the terminal receives the encryption instruction, which is an instruction for executing a preset instruction string in the encryption sub-node of the EADMO node of the DM tree, sent from the DM server, performing, the encryption operation for data of the terminal according to information stored by the encryption mode, the encryption key words and the encryption level sub-nodes in the encryption sub-node of the EADMO node of the DM tree to generate the encrypted data state information.