Non-uniqueness is always,by nature,the problem we face in inversion processes,and it is caused by the phenomenon of equivalence in field,erroneous,discrete,and finite features in observation and the influence of other sources.Many authors have done lots of researches in this field in order to get more reliable outcomes,and joint inversion is a thriving one where different kinds of data are combined to derive certain information simultaneously or sequentially.One of these studies is that the prior information such as the geological,drilling and seismic data will be used as constraints,while the inversion procedure can be controlled.In this article we use a new method with the goal of better obtaining the three-dimensional density contrast interface.This prior seismic data integrated in the inversion can play a constrained role in the procedure which means that the depth of the Moho interface at the seismic location will be restricted.It thus can provide a credible result.In order to test its effect,this program is applied in a field example―derivation of Moho geometry in Northeast China. Non-uniqueness is always, by nature, the problem we face in inversion processes, and it is caused by the phenomenon of equivalence in field, erroneous, discrete, and finite features in observation and the influence of other sources. Many authors have done lots of researches in this field in order to get more reliable outcomes, and joint inversion is a thriving one where different different of of data are combined to derive certain information simultaneously or sequentially. One of these studies is that the prior information such as the geological, drilling and seismic data will be used as constraints, while the inversion procedure can be controlled. this article we use a new method with the goal of better obtaining the three-dimensional density contrast interface. This prior seismic data integrated in the inversion can play a constrained role in the procedure which means that the depth of the Moho interface at the seismic location will be restricted. It thus can provide a credible result. In order to tes t its effect, this program is applied in a field example-derivation of Moho geometry in Northeast China.