||A perylene-based reactive mesogen (PBRM) is newly programmed and synthesized for the multifunctional optical thin film. PBRM has two ionic parts and two reactive parts. So, PBRM shows nematic liquid crystal phase in water solution and optical thin film can be fabricated by the simple shear process and the subsequent photo-polymerization. The fabricated thin film can work for the in-cell coatable polarizer as well as the planar LC ailgnment layer. These properties were demonstrated by the spectroscopic results combined with optical observations. It was found that the molecular long axis of PBRM are aligned perpendicularly to the shear direction. And 5CB molecules are aligned parallel to the PBRM molecule in cell. Furthermore, TN and IPS test cells were successfully demonstrated by using PBRM optical thin film. This work was supported by the BRL (2015042417), MOTIE-KDRC (10051334), Mid-career Researcher Program (2016R1A2B2011041) and the BK21 Plus program of Korea.