Abstract: As a new exploration method，Ground Penetrating Radar（GPR） is used in the landmine exploration field.However，in the GPR echo signal，there are some noises and weak object echo signal are often obscured with the strong interference signals.In order to improve the signal-to-noise and identifying the landmine，a new method based on information entropy is presented，the method combine with the wavelet packet de-noise method.The experiment results show the direct wave and background noise can be effective reduced and the object signal can be extracted when the methods are adopted.