Nowadays, in most of the unauthorized internet access monitoring systems, there is no satisfactory method on access control with USB storage device. The common way is to take off the USB port from the computer to prohibit the use of USB storage devices. This method directly leads to lose the convenience by using USB storage devices, and also no longer be able to use other equipment based on the USB port. This paper introduces an access control model for USB storage device. It has user authentication, and operates by a client to read and write the USB storage device. It is a good solution for USB storage device access control problem. At the same time, this paper also gives a new approach to prevent the spread of the virus by USB storage devices.