Abstract: A multi-spectral reconstruction method based on adaptive finite element comprising the following steps: discretizing the diffusion equation in the object domain on the single spectral; establishing the relationship between the boundary measurement data and the unknown source variables on single spectral based on a posteriori permissible source region selection method, and forming the objective function based on the multi-spectral characteristics and the regularization method; optimizing the objective function and determining if the reconstruction shall be stopped or not; and if the reconstruction shall not be stopped, refining the mesh adaptively by using a posteriori measure method, and then returning to the first step to continue the reconstruction process.