A method of erasing a cloud host in a cloud-computing environment, comprising: receiving a request of secure erasing a cloud host, comprising: receiving a selection operation from a user, and determining the cloud host to be erased and a corresponding erasing manner according to the selection operation, and shutting down the cloud host to be erased on the corresponding host machine according to the request of secure erasing the cloud host; determining an input/output, I/O, resource consumption of a disk according to a disk space, a space occupied by the cloud host to be erased, and the corresponding erasing manner; returning a notification to the user in the case that the I/O resource consumption is over a preset threshold value to suggest that the disk I/O resource consumption is over consumed and the erasing manner should be re-selected; generating an erase instruction according to the request of secure erasing the cloud host in the case that the I/O resource consumption is not over the preset threshold value; sending the erase instruction to a secure erasing server, such that the secure erasing server calls a secure erasing daemon process on a corresponding host machine according to the erase instruction, and erases the cloud host to be erased from the host machine via the secure erasing daemon process, comprising: sending the erase instruction to the secure erasing server, such that the secure erasing server forwards the erase instruction to the secure erasing daemon process on the host machine; adding, by the secure erasing daemon process, a file corresponding to the cloud host to be erased to an erase queue according to the erase instruction, and generating a corresponding erase task; configuring the erase task in the erase queue with low priority via the secure erasing daemon process; and executing, by the secure erasing daemon process, the erase tasks in the erase queue respectively with low priority according to an erasing manner corresponding to the cloud host to be erased. receiving a request of secure erasing a cloud host, comprising: receiving a selection operation from a user, and determining the cloud host to be erased and a corresponding erasing manner according to the selection operation, and shutting down the cloud host to be erased on the corresponding host machine according to the request of secure erasing the cloud host; determining an input/output, I/O, resource consumption of a disk according to a disk space, a space occupied by the cloud host to be erased, and the corresponding erasing manner; returning a notification to the user in the case that the I/O resource consumption is over a preset threshold value to suggest that the disk I/O resource consumption is over consumed and the erasing manner should be re-selected; generating an erase instruction according to the request of secure erasing the cloud host in the case that the I/O resource consumption is not over the preset threshold value; sending the erase instruction to a secure erasing server, such that the secure erasing server calls a secure erasing daemon process on a corresponding host machine according to the erase instruction, and erases the cloud host to be erased from the host machine via the secure erasing daemon process, comprising: sending the erase instruction to the secure erasing server, such that the secure erasing server forwards the erase instruction to the secure erasing daemon process on the host machine; adding, by the secure erasing daemon process, a file corresponding to the cloud host to be erased to an erase queue according to the erase instruction, and generating a corresponding erase task; configuring the erase task in the erase queue with low priority via the secure erasing daemon process; and executing, by the secure erasing daemon process, the erase tasks in the erase queue respectively with low priority according to an erasing manner corresponding to the cloud host to be erased. sending the erase instruction to the secure erasing server, such that the secure erasing server forwards the erase instruction to the secure erasing daemon process on the host machine; adding, by the secure erasing daemon process, a file corresponding to the cloud host to be erased to an erase queue according to the erase instruction, and generating a corresponding erase task; configuring the erase task in the erase queue with low priority via the secure erasing daemon process; and executing, by the secure erasing daemon process, the erase tasks in the erase queue respectively with low priority according to an erasing manner corresponding to the cloud host to be erased.