Due to the frequency sharing, Electro Magnetic Compatibility between GPR and Mobile Telephone System is crucial. In the current study, the properties of the random RFI signal received by GPR are analyzed in detail, and the differences between the random RFI and target signal are presented in wavelet field. Furthermore, the method of random RFI suppression based on wavelet transform is proposed. Additionally, the two types of data are collected to validate the performance of the method. Finally, the experimental results prove the effectiveness of the method.