The imaging principle and the structure of a Hadamard transform spectral imager with a digital micromirror device are presented. A phenomenon of energy excursion which is caused by mismatching of the mask unit size and the detector pixel size is expatiated. To fix the recovery images, a matrix correction algorithm is proposed. The 7order images of plants acquired by the Hadamard transform spectral imager are used and the correction algorithm is operated on the recovery images with error, which reduces the phenomenon of dark stripes effectively. In order to improve the image quality of the recovery images, two dots in and off two adjacent dark stripes are selected to show the spectrum curves. The results show the close spectrum curves of the dot off dark stripes and the different curves of the dot in dark stripes. The comparison illustrates the validity of the correction algorithm.