A novel liquid crystal phase modulator (LCPM) of 2D liquid crystal array with parallel alignment was fabricated. And experiments of Zernike polynomial production and distorted wavefront modulation were conducted on the Zygo interferometer with the LCPM. The wavefront profiles of the first 2nd to 8th Zernike polynomial were produced successfully. Sixteen Zernike polynomials were used to modulate the distorted wavefront, the peak-to-valley value (PV) was improved from 0.831λ before modulation to 0.444λ after that, root means square (RMS) from 0.181λ to 0.066λ, and Strehl ratio (SR) from 0.257 to 0.844. The results indicated that the quality of imaging of optical systems was greatly improved when the parallel alignment LCPM is used to modulate the distorted wavefront.