A wavelet-homotopy hybrid inversion algorithm for inverse problem of ground penetrating radar (GPR) is proposed.Wavelet is applied to separate inverse problem into different scales.In the maximum scale,initial value of the next scale is found by a homotopy method.In other scales,iteration process is carried out to obtain the global minimum point.The algorithm takes advantages of wavelet analysis and homotopy inversion method.It shows high capability of global search.