At present, Glass Fibre Reinforced Polymer (GFRP) materials are widely used in oil and gas gathering and transportation, crude oil storage, and sewage treatment due to their superior material characteristics. Due to production complexity, difficulties in quality control and harsh environment, GFRP structures often contain defects (i.e. delamination, water intrusion and crack). Such defects in GFRP storage tanks and GFRP pipelines in oil fields may severely threaten the safety of oil and gas production. In this work, a Capacitive Imaging (CI) system with an arrayed sensor was designed to achieve efficient Non-destructive Evaluation (NDE) of GFRP structures used the oilfields with high accuracy. The proposed system, which includes a software based lock-in amplifier and a channel correction module, were tested using specimens with artificially prefabricated defects. The test results show that the system is compatible with arrayed capacitive probe and is promising in the efficient and high-accuracy NDE of GFRP structures.