Method and device for unlocking file

The invention provides a method and device for unlocking a file. The method comprises the steps that deletion operation or write operation tries to be carried out on the target file; if the deletion or write operation cannot be executed on the target file, the attribute of the target file is obtained; if the attribute of the target file is read only, a user-defined application program interface for changing the file attribute is called to remove the read only attribute of the target file. A provided file unlocking and shredding mechanism is safe, reliable and high in success rate, a file self-protection behavior of a rogue program can be recognized in a complex client side environment and can be resisted, and the resisting capacity to the attack and defense of a driving-level rogue program is enhanced.