A method for orientation of liquid crystals in a micro/nano region formed by polymer strips on the basis of laser direct writing, comprising the following steps: step 1, preparing samples for forming a micro/nano structure in said micro/nano region, wherein said samples are photopolymerizable organics spin-coated on substrates, wherein said polymerizable organics are SU-8 photoresists; step 2, forming the micro/nano structure in said micro/nano region through laser direct writing by a laser direct writing system continuously changing relative positions between a laser focus and said photopolymerizable organics, said laser direct writing using a titanium-sapphire femtosecond laser with a wavelength of 800 nm, a repetition frequency of 1 kHz and a pulse width of 130 fs, and using a microobjective with an amplification factor of 40 and a numerical aperture of 0.6, wherein fine structures on side walls of polymer strips are formed by a single incident light beam, wherein the dimension of each of said micro/nanostructure varies from micrometer to nanometer scale exceeding the diffraction limit of said single incident light, wherein said forming of said micro/nano structure is based on a single photon photopolymerization technology, two-photon photopolymerization technology or on a multi-photon photopolymerization technology, wherein based on a difference in a refractive index of a polymerization area, a non-polymerization area, and a substrate, reflected light generated on an optical surface of a periphery of the polymerization area interferes with the incident light beam and thereby forms stable patterns of standing waves on an outside of the polymerization area so as to generate the fine structures; step 3, post-processing the obtained sample to remove unpolymerized photopolymerizable organics to obtain a micro/nano structure constituted by polymer stripes, said micro/nano structure being a one-dimensional structure, a two-dimensional structure, or a three-dimensional structure; and step 4, injecting liquid crystals into the built micro/nano structure to generate spontaneous orientation of said liquid crystals, where liquid crystal molecules perform self-orientation in said micro/nano region, wherein said spontaneous orientation of said liquid crystals is generated by said fine structures on said side walls of said polymer strips which form said micro/nano structure. step 1, preparing samples for forming a micro/nano structure in said micro/nano region, wherein said samples are photopolymerizable organics spin-coated on substrates, wherein said polymerizable organics are SU-8 photoresists; step 2, forming the micro/nano structure in said micro/nano region through laser direct writing by a laser direct writing system continuously changing relative positions between a laser focus and said photopolymerizable organics, said laser direct writing using a titanium-sapphire femtosecond laser with a wavelength of 800 nm, a repetition frequency of 1 kHz and a pulse width of 130 fs, and using a microobjective with an amplification factor of 40 and a numerical aperture of 0.6, wherein fine structures on side walls of polymer strips are formed by a single incident light beam, wherein the dimension of each of said micro/nanostructure varies from micrometer to nanometer scale exceeding the diffraction limit of said single incident light, wherein said forming of said micro/nano structure is based on a single photon photopolymerization technology, two-photon photopolymerization technology or on a multi-photon photopolymerization technology, wherein based on a difference in a refractive index of a polymerization area, a non-polymerization area, and a substrate, reflected light generated on an optical surface of a periphery of the polymerization area interferes with the incident light beam and thereby forms stable patterns of standing waves on an outside of the polymerization area so as to generate the fine structures; step 3, post-processing the obtained sample to remove unpolymerized photopolymerizable organics to obtain a micro/nano structure constituted by polymer stripes, said micro/nano structure being a one-dimensional structure, a two-dimensional structure, or a three-dimensional structure; and step 4, injecting liquid crystals into the built micro/nano structure to generate spontaneous orientation of said liquid crystals, where liquid crystal molecules perform self-orientation in said micro/nano region, wherein said spontaneous orientation of said liquid crystals is generated by said fine structures on said side walls of said polymer strips which form said micro/nano structure.