Embodiments of the present application provide a touch control method and device based on projection screen, and a projection device, and relates to the technical field of projection screen control. The method comprises the following steps of: determining all idle receivers which do not receive infrared signals on the border; determining a barrier region of an infrared signal according to the idlereceiver; determining a touch position, wherein the touch position is an inscribed ellipse of the barrier region; determining an operation instruction corresponding to the touch position in the projected image; controlling the projection screen according to the operation instruction. The method, apparatus and apparatus shown in the embodiments of the present application are not only simple to operate and helpful to improve the user experience, but also have higher control accuracy and sensitivity.