The invention discloses a method for realizing bi-operation system starting of terminal equipment by using a USB (universal serial bus) controller and belongs to the technical field of dual operation system starting of the user terminal equipment. The method is characterized by including on a single hard disk provided with a working area and a free area, judging whether the USB controller is inserted or not by a BIOS (bi-operation system); if yes, executing a modified guide file GRLDR in the USB controller, verifying PIN of a user, loading a secret key, guiding to enter a reserved partition, executing a decryption program to decrypt the working area, and then entering the working area; if not, guiding to enter the free area by an MBR (master boot record), executing a partition boot record (PBR), in the type of BOOTMGR, of the free area, and entering the free area. Different from other methods for realizing bi-operation system starting through double hard disks, the method has the advantages that a mode of realizing bi-operation system starting through the same hard disk and multiple partitions is used, and through an encryption mechanism of a working area operation system, safety of the working area operation system is guaranteed, cost is lowered, and efficiency is improved.