A universal serial bus (USB) control device and a control method thereof are provided. The USB control device includes multiple host interfaces, multiple USB ports, a bus physical layer circuit, a microprocessor, and a bus schedule controller. The bus schedule controller controls the bus physical layer circuit according to a USB task. The microprocessor obtains a USB task command through the host interface, which includes a USB port number of a specific host interface. The microprocessor queries the USB port number of the specific host interface based on an index lookup table to correspond to a specific USB port, generates the USB task according to the specific USB port, and transmits the USB task to the bus schedule controller. The index lookup table is configured to record a relationship between a part of the USB port that each host interface is responsible for and the USB port number.