The degradable optical alignment technology and its main effects on TFT-LCD are studied. The anisotropy of PI shows a trend from increasing to decreasing as the exposure dose increases and the main curing time extends. The anisotropy of PI, which is a common representation of the alignment ability of PI, performs best at 550 mJ/cm2 ultraviolet treatment and 30 min curing time. In addition, the anisotropy of PI keeps increasing as the main curing temperature increases from 230 ℃ to 250 ℃. Results also demonstrate that the complete optical alignment has no obvious effect on the electrical properties of TFTs. Compared to rubbing process, optical alignment shows huge advantages of contract ratio. The contract ratio of optical alignment product is about 1 500, approximately 50% higher than that of rubbing product, due to the low pre-title angle (about 0.2°).