The invention provides a supporting axial force servo system adopting displacement as a servo target and a measurement and control method thereof. The system comprises steel supports, supporting heads and a numerical control pump station which are arranged in a foundation pit envelope enclosure, wherein the supporting heads are provided with displacement sensors; the displacement sensors are arranged on the end parts of the steel supports; the displacement sensors and the steel supports form combined bodies; the two ends of the combined bodies are fixedly connected with relative two sides of the foundation pit envelope enclosure; the numerical control pump station is connected with the supporting heads through an oil pipe and a cable; and the numerical control pump station controls and drives the supporting heads to move according to axial force data measured by the supporting heads and displacement data measured by the displacement sensors. Through the technical scheme, the technical problem that displacement cannot be accurately controlled due to the fact that pressure is complex when axial force is adopted as the servo target is solved, and the purpose that displacement and deformation of the side wall of a foundation pit are strictly controlled during the excavation process of the foundation pit is achieved.