spectral imagers use a 2-dimensional detector domestically and abroad,anather excellent approach to new method of computational spectral is studied.Making use of an 1-dimension detector instead of a 2-dimension detector to get a 2-dimensional data cube holding the spetral information and the spatial information of eath ground object.By the method of characteristics decoupling,making high precision reconstruction of compressed data.Theoretical analysis and simulation show that it not only ensures the imaging quality but also reduces the dimension of the detectors and complexity of imaging system greatly