The virtual machine includes a receiving module, an instruction assigning module, a downloading module, an application registry maintenance module, a state switching module, a storage managing module, and a communication module. The state switching module is configured to in response to determining that it is required to move the code segment, allocate a storage space of the off-chip FLASH for the code segment of the application to be loaded, acquire a second base address of the code segment of the application to be loaded, and modify the current running address as the second base address. The off-chip FLASH is configured to store the code segment of the application to be loaded on the off-chip FLASH.