How to align the spectral systems of Offner concentric imaging spectrometers with convex gratings was researched. Based on the principle of dual-beam interference and characteristics of concentric systems,an interferometric alignment method for the Offner imaging spectrometers with convex gratings was proposed.With this method ,the primary and tertiary mirrors of Offner imaging spectrometers were aligned firstly. As the defocus of single spherical mirror could not be aligned to zero,the relative defocus was introduced to adjust the defocuses of the two mirrors to achieve the concentricity. Furthermore,because the concave compensator could not test the convex mirror,the convex grating was arranged according to reading spectrogram directly to complete concentric alignment with high precision. The result indicates that the interferometric alignment can achieve the dist