Method and device for achieving magnifying lens on touch screen and host

The embodiment of the invention provides a method and device for achieving magnifying lens operation on a touch screen. The method and device are applied to an electronic device which has the magnifying lens functions and is provided with a touch screen. The method comprises the steps that input operation on the touch screen is acquired; whether the target object of the input operation is a magnifying lens or not is judged according to the input operation, and if yes, gesture judgment is conducted on the input operation, and a gesture judgment result is obtained; whether the input operation is processed by the magnified target object or not is judged according to the gesture judgment result, and if yes, the input operation is converted and the conversion result is transmitted to the magnified target object in an unvarnished mode; whether content is updated in a coordinate area corresponding to the transmitted and magnified target object or nor is judged, and if yes, the display content of the magnifying lens is updated. According to the method for achieving the magnifying lens operation on the touch screen, modes can be automatically selected. The embodiment of the invention further provides a host.