An operation method of a touch screen and a touch screen device are provided by the present disclosure, and the method comprises: acquiring an input trajectory on the screen firstly; then determining whether the input trajectory is consistent with a predetermined trajectory; zooming in a target region on the screen that corresponds to a current touch point of a touch medium if the determination result is “yes”; detecting in the zoomed-in target region a touch-screen operation instruction; and executing a corresponding operation according to the touch-screen operation instruction. Thereby, the present disclosure can reduce occurrences of mis-touches in the process of operating the touch screen and make the touch screen very convenient to use by the user.