In order to improve the accuracy and the speed of reconstructed image in the pre-magnification digital holographic microscopy system with spherical reference wave, the generalized linear reconstructing algorithm based on homomorphic signal processing (GL-HSP) is analyzed by computer simulation and experimental verification. Through using the algorithms based on fast Fourier transform (FFT) method and GL-HSP algorithm to reconstruct the intensity and phase information of texted samples, the reconstructed results clearly show that the GL-HSP algorithm not only has higher reconstructed accuracy, but also has higher reconstructed speed. As the GL-HSP algorithm chooses the whole quadrant as the filtered area, it has all of the high frequencies. So the GL-HSP algorithm is more suitable for high-accuracy reconstructing the micro-subjects. At the same time, the results of standard deviation in the experimental date quantitatively show the superiority of the GL-HSP algorithm.