Abstract: This paper makes full use of the merits of different methods in analyzing seismic and gravity fields. Taking the Tianjin-Beijing-Chicheng high-precision and high-resolution deep seismic sounding profile (DSS) as an example and using the model of seismic interpretation as a constraint, the paper conducted forward and inverse data fitting and obtained the density structure of the profile. Then re-fitted and amended the model result of the seismic interpretation of both sides of the profile. Practice has shown that, with joint inversion of seismic and gravity data, the shortcomings and deficiencies of a single method are overcomed, so that the obtained results are closer to the actual situation of the studied area.