The invention provides a method and a device for generating test cases on the basis of mainframe code analysis. The method includes analyzing mainframe program codes, and recognizing each function module according to keywords of coding languages; according to all operations of each function module on resources, generating all compounding piles of the function modules, and inserting the compounding piles into programs of the function modules; executing a program, collecting information in an operation array, filtering and cleaning the collected information, respectively neatening information of the compounding piles corresponding to the program according to the compounding piles, and generating effective information; deeply analyzing the effective information, and making a resource directed network map from the resources according to the sequence of operators; traversing the resource directed network map according to a traversal algorithm to obtain all paths, and generating all the test cases taking the resources as clues. The method and the device provide the full-volume test cases, taking the resources as the clues, to existing huge mainframe system testing.