A method for accessing a storage device, applied to a computer system, wherein a virtual machine runs in the computer system, an I/O adapter is further configured in the computer system, and the method comprises: acquiring, by the I/O adapter, an access request from the virtual machine, wherein the access request carries virtual address information of a to-be-accessed storage area; generating, by the I/O adapter, an access instruction according to the access request, wherein the access instruction carries the virtual address information and an identifier of a virtual channel of the virtual machine, wherein the virtual channel is used to connect the virtual machine to a storage device target, the virtual machine corresponds to the virtual channel on a one-to-one basis, and the storage device target is configured to manage access to the storage device; and sending, by the I/O adapter, the access instruction to the storage device target; wherein at least one cache queue is configured in the I/O adapter, and each cache queue corresponds to each virtual channel on a one-to-one basis; and after the acquiring, by the I/O adapter, an access request from the virtual machine, the method further comprises: putting, by the I/O adapter, the access request of the virtual machine in a first cache queue corresponding to the virtual channel of the virtual machine; before the generating, by the I/O adapter, an access instruction according to the access request, the method further comprises: querying, by the I/O adapter, a preset first correspondence according to an identifier of the virtual machine, and determining the identifier of the virtual channel, wherein the preset first correspondence comprises a correspondence between an identifier of each virtual machine and an identifier of each virtual channel; wherein after the sending, by the I/O adapter, the access instruction to the storage device target, the method further comprises: acquiring, by the I/O adapter, a feedback message from the storage device target, wherein the feedback message comprises an execution result of the access instruction and the identifier of the virtual channel of the virtual machine; and determining, by the I/O adapter, the virtual machine according to the identifier of the virtual channel, and sending the execution result of the access instruction to the virtual machine. acquiring, by the I/O adapter, an access request from the virtual machine, wherein the access request carries virtual address information of a to-be-accessed storage area; generating, by the I/O adapter, an access instruction according to the access request, wherein the access instruction carries the virtual address information and an identifier of a virtual channel of the virtual machine, wherein the virtual channel is used to connect the virtual machine to a storage device target, the virtual machine corresponds to the virtual channel on a one-to-one basis, and the storage device target is configured to manage access to the storage device; and sending, by the I/O adapter, the access instruction to the storage device target; wherein at least one cache queue is configured in the I/O adapter, and each cache queue corresponds to each virtual channel on a one-to-one basis; and after the acquiring, by the I/O adapter, an access request from the virtual machine, the method further comprises: putting, by the I/O adapter, the access request of the virtual machine in a first cache queue corresponding to the virtual channel of the virtual machine; before the generating, by the I/O adapter, an access instruction according to the access request, the method further comprises: querying, by the I/O adapter, a preset first correspondence according to an identifier of the virtual machine, and determining the identifier of the virtual channel, wherein the preset first correspondence comprises a correspondence between an identifier of each virtual machine and an identifier of each virtual channel; wherein after the sending, by the I/O adapter, the access instruction to the storage device target, the method further comprises: acquiring, by the I/O adapter, a feedback message from the storage device target, wherein the feedback message comprises an execution result of the access instruction and the identifier of the virtual channel of the virtual machine; and determining, by the I/O adapter, the virtual machine according to the identifier of the virtual channel, and sending the execution result of the access instruction to the virtual machine.