As a new smart material, dielectric electroactive polymers (DEAP) have shown great promise in the fields of sensing and actuation owning to their excellent overall performance, including large deformation, high efficiency and energy density. Based on the capacitance change principle of the polymer when deformed, a sensing cell composed of an outer frame, an inner frame and a sheet of DEAP film that was divided into four partitions coated with flexible electrode was designed and implemented. When the DEAP film was stretched or shrunk by the mobile inner frame, the flexible electrodes on both sides of the film come closer together or away each other, respectively, leading to changes in capacitance. A geometrical model of the proposed sensing cell was developed and the relationship between the capacitance of the sensing cell and the displacement of the inner frame was deduced. A differential approach was used to measure the variation of the capacitance of the parts face to face, and the capacitance difference of two opposite parts in function of the inner frame inplane displacement was developed. Moreover, 2-DOF angular sensor by the sensing cell was designed and applied to angle measurement, and similarly, a differential approach was used to obtain the curve of the capacitance difference with the joint’s rotational angle. The experimental sensitivities of X-translation, Y-translation, X-rotation and Y-rotation were respectively -57.2pF/mm, -58.0pF/mm, -139.4pF/(°) and 141.6pF/(°), which were agreed well with the theoretical results. The research result verifies the feasibility of the application of DEAP in displacement sensor and angle sensor.