A feedback system for identifying an external force, includes an operation plate and a pressure-sensing unit. The pressure-sensing unit includes an elastic member supporting the operation plate and a pressure sensor inside the elastic member. The pressure sensor includes a pressure sensitive film. An inner side of the elastic member is filled with fluid material which acts on the pressure sensitive film. The operation plate is driven by the external force to be slant which extrudes the elastic member to deform so as to change fluid pressure of the fluid material limited in the elastic member, and such change of the fluid pressure can be sensed by the pressure sensitive film of the pressure sensor so as to identify the movement and the intensity of the external force.