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 projection display apparatus comprises a projection screen and a plurality of optical sensors with two-dimension disperse layout in the back of the projection screen. The projection display apparatus further comprises an acquiring element configured to receive first light through first optical sensor of the plurality of optical sensors, wherein the first optical sensor is one or more of the plurality of optical sensors; a determining element configured to determine first coordinate information of the first optical sensor on the projection screen if the light intensity of the first light is within first light intensity range; and a sending element configured to send the first coordinate information to a computing device.