The conventional Fourier ptychographic microscopy (FPM) is a computational imaging approach, which stitches together a sequence of low-resolution (LR) images captured by different angles illumination. However, the limitation of processing efficiency in capturing LR images is gradually becoming obvious. Utilizing the principle, aimed at reducing the amount of captured measurements and decreasing acquisition time, this paper proposes an optimized spectral sampling scheme. In this method, the importance of the spectra in the spectrum domain is analyzed and the more informative parts are selected. The acquisition efficiency can be increased because the selected images are captured and applied into the conventional FPM routine. Compared with the conventional FPM, experimental results significantly indicate that the redundancy of information and the time of image collection could decrease without debasing the quality of the reconstruction.