An integrated test method on a multi-operation system (OS) platform for performing an integrated test of a file system and disk performance in a computer with an extended firmware interface (EFI) system environment on multiple OS platforms is provided. The method includes the following steps. Scan sectors of an entire physical hard disk and perform a hardware underlying test of a disk device in the EFI environment; select and load an OS, then enter the OS environment to test the file system and the disk performance in the system environment; exit from the OS and return to the EFI environment to summarize a test result; determine whether it is necessary to load other OSes, if necessary, return and load other OSes, and if not, send the summarized test result to a server terminal for analysis and processing.