The invention discloses a system for automatically testing stability of an application program interface and a method. The system comprises an operation controller, a monitor and log generator, a use case generator, a use case template library and an operation strategy library, wherein the operation controller is respectively connected with the monitor and log generator, the use case generator and the operation strategy library; the use case generator is connected with the use case template library; according to a backstage interface type of the application program, the operation controller is used for reading a test strategy of the operation strategy library, calling the use case generator to generate a test use case, reading the above test use case for test operation finally, and monitoring operation of the test strategy and a restoration function in the case of abnormal test. The system can automatically generate the test use case for the application program backstage interface, the test use case coverage is wide, the strategy can be self defined for operating the test, an automatic test operation function is provided, and a detailed test log can be generated automatically.