The embodiments of the present invention provide a method for switching a working mode, a USB device, and a host device. The method for switching a working mode includes: determining, according to the osvc key value in the registry of a host device, that a driver for a second working mode is installed on the host device, after the USB device is connected to the host device; and switching the current working state of the USB device from a first working mode to the second working mode. In the embodiments of the present invention, neither special auxiliary program nor additional driver needs to be developed. Therefore, the solution is easy to implement and a problem of incompatibility will not occur.