Abstract: With the wide application of liquid crystal display technique in most fields and the promotion of new technologies in recent years, much endeavor has been made to improve its performance. The photoelectric characteristic is an important parameter in the application of liquid crystal devices. The electro-optical properties, threshold voltage and viewing angle of liquid crystal were studied by using laser measurement, and the distortion characteristics of liquid crystal molecules affected by the alternating electric field after re-orientation were analyzed. The twist angle of liquid crystal molecules and transmittance under different voltage conditions were also tested. The results show that this method is feasible. The twisted nematic liquid crystal has 0.92 V lower threshold voltage and relatively steep electro-optical curve, and it possessed good view angle properties from -60 to +50 in the horizontal direction and from -40 to +20 in the vertical direction. The conclusion provides scientific basis for the design and manufacture of polarizer.