You need to find the production tool corresponding to the USB flash drive (you can read the main control information of the USB flash drive through the chip wizard or similar software).

Run the mass production tools, check the CDROM item and ISO file path in the tool settings, save the settings after the settings are completed, insert the U disk into the computer, and run the set mass production tools. After the mass production operation, the startup disk of USB-CDROM mode is completed. Turn off the mass production tools and plug in the USB flash drive again, and you will find that there are more CDROM drive symbols in the mobile storage device.