A USB port shared control method executed by a hypervisor controlling port sharing among virtual machines and having a physical USB host controller including a physical register, the virtual machines each including a virtual USB host controller having a virtual register. The method includes performing sharing by: selectively allocating the physical register to the virtual register of a subject virtual USB host controller provided in a subject virtual machine of the plurality of virtual machines to occupy and unitize the USB port by the subject virtual machine, and directly reading or writing of the physical register by the subject virtual machine via the subject virtual USB host controller, to thereby allow the subject virtual USB host controller to directly control the physical USB host controller. More particularly, the allocating, reading and writing are switched from subject virtual machine to subject virtual machines to facilitate sharing.