A virtual disk processing method, applied to a host that supports virtualization, wherein a first virtual machine runs on the host, and the method comprises: receiving delete information sent by a client system of the first virtual machine, wherein the delete information is generated by the client system after a designated file is deleted from the first virtual machine, and the delete information comprises an offset corresponding to the designated file and a size of the designated file; determining, according to the delete information, at least one data cluster that is in a first virtual disk and that is corresponding to the designated file, wherein the first virtual disk is a virtual disk corresponding to the first virtual machine; setting the at least one data cluster to be available; determining, according to a storage mapping table, a target physical disk block corresponding to the at least one data cluster, wherein a correspondence between a data cluster in the first virtual disk and a physical disk block is recorded in the storage mapping table; and setting the target physical disk block to be available; wherein before receiving said delete information sent by the client system of the first virtual machine, the method further comprises: dividing each virtual disk on the host into clusters, so that each virtual disk is divided into at least one data cluster; and allocating a data cluster identifier to each data cluster, wherein the first virtual machine continues to run and is not stopped while the steps of receiving the delete information, determining the at least one data cluster, setting the at least one data cluster to be available, determining the target physical disk block, and setting the target physical disk block to be available are performed. receiving delete information sent by a client system of the first virtual machine, wherein the delete information is generated by the client system after a designated file is deleted from the first virtual machine, and the delete information comprises an offset corresponding to the designated file and a size of the designated file; determining, according to the delete information, at least one data cluster that is in a first virtual disk and that is corresponding to the designated file, wherein the first virtual disk is a virtual disk corresponding to the first virtual machine; setting the at least one data cluster to be available; determining, according to a storage mapping table, a target physical disk block corresponding to the at least one data cluster, wherein a correspondence between a data cluster in the first virtual disk and a physical disk block is recorded in the storage mapping table; and setting the target physical disk block to be available; wherein before receiving said delete information sent by the client system of the first virtual machine, the method further comprises: dividing each virtual disk on the host into clusters, so that each virtual disk is divided into at least one data cluster; and allocating a data cluster identifier to each data cluster, wherein the first virtual machine continues to run and is not stopped while the steps of receiving the delete information, determining the at least one data cluster, setting the at least one data cluster to be available, determining the target physical disk block, and setting the target physical disk block to be available are performed.