In this paper, using RADAR signal to carry target information, this paper provides a novel method to detect grounding grid without excavation. Random noise transmitting signal is used to prevent the electromagnetic interference in power plant and substation. The random signal with bell-like power spectrum is proved having the best performance. With increase in the variance, resolution of the random transmitting signal is improved. The performance of the designed transmission signal is shown with ambiguity function. This paper presents some experimental results obtained from designed RADAR detecting the transmitted signal.. All conductors of the testing grounding grid are imaged and differentiated effectively.