Based on the principle of hadamard transform spectral imager, through the mathematical modeling of its spectral imaging process, the spectral information aliasing and spatial information aliasing caused by hadamard code mask modulation are deeply analyzed, and an algorithm is proposed to remove aliasing according to the spectral offset.The target data is collected by the self-developed hadamard transform spectral imager. Data cube reconstruction is accomplished by the proposed algorithm of removing aliasing. Finally, the 3D data cube is restored successfully. The spatial information aliasing and spectral information aliasing are effectively removed, and the correctness of the proposed algorithm is verified.