Disclosed in the application are a method and device for identity authentication. The method comprises: when the terminal is in the specified stress state, action attribute information of the terminal is collected; the action attribute information is processed by matching with preset sample information; if the action attribute information is matched with the sample information, the authentication is successful, and if the action attribute information is not matched with the sample information, the authentication is failed. By the above method, the terminal can automatically collect the corresponding action attribute information in the process that users perform certain specified operation, and then match and compare with the preset standard information to authenticate the identity of the current user using the terminal. Therefore, the terminal can collect the action attribute information and set up or authenticate it without entering a specific acquisition mode in the process that the user operates and uses the terminal. It avoids interfering with the use of users, and also effectively improves the convenience of operation.