The wave equation finite-difference method is used to the synthetic seismic records in the seismic prospecting of shallow high resolution in urban active fault detection. For improving the resolution and prospecting efficiency of the seismic modeling, some suitable finite-difference method, source wavelet, boundery conditions and dispersion elimination method are adopted. The result shows that the seismic modeling can be used to analyse the influence of the stratigraphic thickness and the obliquity, depth and scale of fault on the seismic synthetic common-shot profiles. From comparision this common-shot profiles with the real experimental data, we can approximately determine the location, scale and depth of fault in field work. The method can improve the prospecting efficiency and resolution rate in the shallow seismic prospecting in urban active fault detection.