The present invention provides a method for termination detection of optical alignment of liquid crystal material, which includes: under influence of electrical field, irradiating light on liquid crystal material so that reactive monomers in liquid crystal material polymerizing; detecting a residual amount or a thickness change value of the reactive monomers in liquid crystal material to determine detected residual amount of reactive monomers or thickness change value in liquid crystal box reaching a default value; when reaching default value, terminating optical alignment of liquid crystal material. The present invention also provides a device for termination detection of optical alignment of liquid crystal material. Through detecting termination of optical alignment, the present invention realizes automatic control of irradiation time in optical alignment to reduce the effect of individual glass substrate variation on optical alignment to avoid affecting reaction process of alignment on reactive monomer.