A pressure sensor, a manufacturing method thereof, a pressure sensing method and a display device are provided. The pressure sensor includes a first electrode, at least two supports on a first surface of the first electrode, an elastic composite electrode on a side of the supports facing away from the first electrode. Two adjacent supports of the supports, the elastic composite electrode and the first electrode define a compressible space, and the at least two supports are formed of an insulating material. The pressure sensor further comprises a second electrode on a side of the elastic composite electrode facing away from the first electrode and an organic light emitting layer between the first electrode and the second electrode, the organic light emitting layer being in contact with one of the first electrode and the second electrode. The pressure sensor has advantages of low power consumption, fast response and high sensitivity.