The present invention discloses an input method for a touch screen comprising a first step of acquiring the coordinates of all current touch points on the touch screen, the method further comprises steps of: (a) comparing and determining whether the distance between any two of the uncompared touch points on the touch screen is greater than or equal to a preset distance, executing the right-key operation of a mouse at the current position of the pointer of the mouse and terminating the current processing flow if it is positive, otherwise proceeding to step (b) if it is negative; (b) determining whether comparison has been made to the distances of all the touch points on the touch screen, and calculating the average of the coordinates of all the current touch points if they have been compared, otherwise returning to step (a). The method of the present invention can implement the right-key function on the touch screen in a convenient, rapid and accurate manner.