Abstract: Under the limitation of survey azimuth,the tomography process of crosswell seismic data is unstable. To improve the stability of imaging process,the well log was introduced into the inversion process and is used to constrain crosswell seismic inversion.The numerical simulation and inversion tests are made on the assumptive model,and the comparative tests between constrained inversion and no constrained inversion are also made.The multiple inversion results show logging constrained inversion improve the stability of tomography process and the precision of imaging result.