A head-mounted display device , comprising: an illumination system , configured to provide an illumination beam (IL), and comprising an aperture stop ; a display device , configured to convert the illumination beam (IL) into an image beam (ML), wherein the image beam (ML) is transmitted and projected to a projection target (P); a lens module , configured to receive and project the image beam (ML); and a waveguide system, configured to guide the image beam (ML), and projecting the image beam (ML) to the projection target (P), wherein the waveguide system comprises a first waveguide element and a second waveguide element , the image beam (ML) is projected to the projection target (P) through the lens module , the first waveguide element and the second waveguide element , the image beam (ML) is converged to a first stop (PA1) within the first waveguide element , the first stop (PA1) is located in the first waveguide element , the image beam (ML) leaves the second waveguide element , and is projected to a second stop (PA2) out-side the second waveguide element , the second stop (PA2) is located at the projection target (P), characterized in that the illumination beam (IL) is converged to a third stop (PA3) within the illumination system , and the aperture stop is located at the third stop (PA3), and wherein the illumination system further comprises an illumination light source , a collimation lens set and a light uniforming element , wherein the illumination beam (IL) provided by the illumination light source is transmitted to the display device through the collimation lens set , the aperture stop and the light uniforming element in sequence. an illumination system , configured to provide an illumination beam (IL), and comprising an aperture stop ; a display device , configured to convert the illumination beam (IL) into an image beam (ML), wherein the image beam (ML) is transmitted and projected to a projection target (P); a lens module , configured to receive and project the image beam (ML); and a waveguide system, configured to guide the image beam (ML), and projecting the image beam (ML) to the projection target (P), wherein the waveguide system comprises a first waveguide element and a second waveguide element , the image beam (ML) is projected to the projection target (P) through the lens module , the first waveguide element and the second waveguide element , the image beam (ML) is converged to a first stop (PA1) within the first waveguide element , the first stop (PA1) is located in the first waveguide element , the image beam (ML) leaves the second waveguide element , and is projected to a second stop (PA2) out-side the second waveguide element , the second stop (PA2) is located at the projection target (P), characterized in that the illumination beam (IL) is converged to a third stop (PA3) within the illumination system , and the aperture stop is located at the third stop (PA3), and wherein the illumination system further comprises an illumination light source , a collimation lens set and a light uniforming element , wherein the illumination beam (IL) provided by the illumination light source is transmitted to the display device through the collimation lens set , the aperture stop and the light uniforming element in sequence. <EOS>