The invention provides a touch sensing circuit and method, a touch screen and a display device, the touch sensing circuit comprises: a touch sensing unit, an output control unit and a detection unit; the touch sensing unit is configured for providing a touch current, and transmitting the touch current to the output control unit; the output control unit is connected with a second control line, a read-out line, the touch sensing unit and the detection unit, for outputting the touch current to the detection unit; the detection unit is connected with a reference voltage terminal, an output terminal, the read-out line and the output control unit, for detecting significant change in the voltage output by the output control unit, thereby determining the location where the touch occurs. The detection accuracy of the detection sensing circuit in determining the occurrence of touch is improved.