1. An isolation method for a management virtual machine, comprising: receiving, by a server, a request message to create a guest virtual machine corresponding to a guest identifier, acquiring, by the server, the guest identifier from the request message; creating, by the server, the guest virtual machine according to the request message; searching, by the server according to the guest identifier, the management virtual machine for a kernel virtual machine corresponding to the guest identifier; accessing the kernel virtual machine to provide a service for the guest virtual machine when the server finds the kernel virtual machine in the management virtual machine; and performing the following steps when the server does not find the kernel virtual machine in the management virtual machine: creating the kernel virtual machine in the management virtual machine; dividing, by the server, code of a service provided for a guest virtual machine by the kernel virtual machine into multiple service components; and running, by the server, the multiple service components in multiple execution environments corresponding to different permissions of the service components, wherein the kernel virtual machine comprises the multiple execution environments.