Embodiments of the present disclosure relate to the field of computer data processing, and provide a data processing method and a smart device, which can effectively resolve a problem of abnormal rewriting of data in a read-only partition of an embedded multimedia card (eMMC) while ensuring that normal upgrading is not affected. The method includes receiving a write protection cancellation command sent by a central processing unit, executing the write protection cancellation command on a specified partition that is in the read-only partition and that is used to store an upgrade file, receiving the upgrade file sent by the central processing unit, writing the upgrade file to the specified partition, after completing writing the upgrade file, sending a write completion message to the central processing unit, receiving a write protection command sent by the central processing unit, and executing the write protection command on the specified partition.