The invention discloses a multipoint touch screen device and a positioning method for multipoint touch, which can identify two or more touch operations. The device comprises a touch panel, infrared LEDs, a projection flexible screen, an infrared camera, a projector, a controller and a computer execution command processor. The infrared LEDs are circumferentially arranged on the transparent touch panel to envelope all infrared lights based on the frustrated total internal reflection principle. When the panel is touched, the total reflection is destroyed and the infrared camera behind the panel can capture the bright spot. An infrared filter plate is placed before the infrared camera to filter off visible lights. The infrared camera collects a touch event and sends touch signals to the controller; the controller process the touch signals and sends the data of touch event and touch position to the computer software for explaining the touch and executes the operations based on the touch event.