Provided are a linearly polarized light conversion element, a manufacturing method and a linearly polarized light conversion system. The linearly polarized light conversion element includes a substrate (1); a metasurface (2) located on the substrate (1); where the metasurface (2) includes at least one light field regulation control region (100), each light field regulation control region (100) includes at least one metasurface functional unit (20), the metasurface functional unit (20) includes an anisotropic sub-wavelength structure (201), and a long-axis direction of each sub-wavelength structure (201) in a same light field regulation control region (100) is the same.