Manufacturing method of 3D display device and grating device thereof

A manufacturing method of a 3D display device and a grating device provides a photopolymerization polymer solution, an electrochromic solution and at least one transparent conductive substrate are provided; mixes a specific quantity X of the photopolymerization polymer solution with a specific quantity Y of the electrochromic solution to produce a grating manufacturing solution; places the grating manufacturing solution between two transparent conductive substrates or at a side of a transparent conductive substrate; projects light through a photomask onto the grating manufacturing solution which is cured to form a transparent fence-shaped isolating element, and a portion of the grating manufacturing solution remains at a fluid state. The devices are manufactured in a primary manufacturing step to improve the manufacturing efficiency. The transparent conductive substrate is placed on a display device and electrically coupled to an electrode portion to complete the production of the grating device of the 3D display device.