Aiming at the Hainan volcanic lava the geological characteristics, the application of geological radar detection technology in the geological environment of signal respond, combined with the added drilling data is compared, established the goal of geological radar image characteristics of geology, summarized the poor geological conditions in the area of geological radar signal response law. Field test shows that the radar reflected wave group of wave characteristic in volcanic lava can distinguish different geological layer reflection wave group, and via studying their relationship and change trend, to achieve the purpose of geological interpretation, and determine the adverse lava geology development stages, for design and construction to provide the reliable foundation material, effective use of survey for the design and construction of the guidance function.