A method includes: obtaining a refresh request of an application, where the refresh request is used to instruct to refresh display data of the application; transferring the refresh request to a display daemon by using a render thread of the application; when communication duration between the render thread and the display daemon is greater than a first time threshold, determining that an exception occurs in the render thread; and when duration in which the display daemon processes the refresh request is greater than a second time threshold, determining that an exception occurs in the display daemon.