The embodiment of the invention discloses a method and a device for processing a dynamic link library (DLL) file. The processing method is characterized in that: the DLL file containing a key code and serving as a resource (specifically a binary resource) is embedded into an application program, wherein the DLL file is not an independent file any more and a cracker cannot easily locate the positions of the key code and the DLL file; and meanwhile, the DLL file is loaded without directly using a Load Library API function any more, the whole loading process is performed in a dynamic loading mode, and the key code of an import function in the DLL file is associated with the actual address of the import function to establish dynamic link by repositioning the actual and virtual addresses of the DLL file and modifying an entry address of the import function in an IAT table so that the cracker has difficulty in judging the time and address of actually loading the DLL file and the technical effect of securely loading the DLL file is achieved.