A manufacturing method of a waveguide and a head mounted display device having the waveguide are provided. The head mounted display device includes a display unit, a first waveguide and a second waveguide. The display unit is configured to provide an image beam. The first waveguide is located between the display unit and the second waveguide. The first waveguide is configured to transmit the image beam to the second waveguide and adjust a light shape of the image beam to maintain a field angle and expand a pupil in a single dimension. The second waveguide is configured to transmit the image beam to outside of the head mounted display device, and the second waveguide can extend a light transmission path and provide a uniform image beam.