The accurate exploration of piedmont complex reservoir is a major problem in geophysical exploration. It's difficult to analyze and predict the distribution law of reservoir sand bodies in piedmont zone because of its complex structural features, rapid formation of lithology and unclear geological structure. In this paper, the importance of low frequency model to the inversion results is studied by taking wedge model in homogeneous medium as an example. And to solve the exploration problems in Shenmu area of Tarim basin of Cretaceous Shushanhe Formation sandstone, we proposed a new method for constructing low frequency model of piedmont complex geological body by using velocity body and attribute body which reflects the sedimentary tendency to supplement the very low frequency (0 to 3 Hz) components, and by using well interpolation model which is controlled by tectonic horizon to supplement 3 Hz to 10 Hz frequency. The method has achieved good results in the evaluation of the target oil and gas exploration in the Kuche foreland basin.