Planar electrical capacitance tomography (ECT) is suitable for non-destructive testing applications such as surface/subsurface defect detection of composite materials, or limited sensor installation. A new planar capacitive sensor with a new structure array is proposed aiming at the problems of poor sensitivity distribution uniformity and low imaging quality of the central region of the square array sensors used in conventional ECT systems. The sensor consists of a honeycomb array of seven sensing electrodes. The new structure array sensor is modeled and analyzed by COMSOLTM professional software, and the electrostatic field boundary conditions are set, and the electric field distribution, electrode capacitance value and sensitivity matrix of the sensor are obtained. By comparing with the 3 x 3 square array sensor of the same size, the key performance of the new structure array sensor, that is, the change value of the electrode capacitance and the uniformity of the sensitivity distribution, is evaluated. What’s more, the physical sensor is manufactured using printed circuit board technology combined with linear back-projection algorithm for image reconstruction, and the imaging performance of the two structures of sensors is verified. The results of numerical imaging experiments and test of reconstructed images show that the new structure array sensor is beneficial to the detection of capacitive sensing signals, improves the uniformity of sensor sensitivity distribution, as well as the imaging quality of the central area of the ECT system.