In order to describe the tectonic stress field distribution of some region in the northeast of Sichuan province, Some researches have been done to reveal the relationship between oil & gas distribution and the tectonic stress field distribution, and to avoid the disaster under the well and finally get the way of how to exploit the oil & gas safely in this area. First, we constructed the model by using Modeleasy, which is a software on 3D geological modeling. The data used in modeling was precisely interpreted in 3 dimension seismic and faults data. Then, we calculated the tectonic field distribution using finite element method based on this model. The result conforms to the drill, and it is consistent with the coefficient of press obtained by inverse.