A electrical capacitance tomography（ ECT） system which based on planar array electrodes sensor is designed. This system is composed of a planar array electrodes sensor system of ECT and a computer imaging interface

and detects the damage and flaw of composite material by using the measuring principle of edge effect of capacitance. The results show that when the glass block material whose dielectric constant is 3. 5 is tested

this system can come out an image with higher resolution ratio

smaller artifacts. This indicates that the system is a simple and effective nondestructive test（ NDT） system with excellent image reconstruction effect.