The embodiments of the disclosure provide apparatus, method and system for location based touch, which can implement location based touch on the image of the projection display apparatus without the requirement of operation of the computing device by the user. A computing device comprises a receiving circuitry configured to receive first coordinate information, wherein the first coordinate information indicates the location of first optical sensor on a projection screen, and the first optical sensor is one or more of a plurality of optical sensors; a determining circuitry configured to determine second coordinate information corresponding to the first coordinate information on a screen of the computing device according to the first coordinate information and coordinate mapping relationship between a projection image and the screen of the computing device; and a performing circuitry configured to perform a touch operation corresponding to the second coordinate information within the screen of the computing device according to the second coordinate information.