The　main　purpose　of　this　work　is　to　propose　a　new　method　to　evaluate　the　concentration　distribution　of　the　hydrogen　jet　by　using　a　He–Ne　laser　through　the　jet.　This　research　attempts　to　apply　the　expression　of　concentration　Gaussian　distribution,　the　refraction　formula　of　inhomogeneous　refractive　index　medium,　and　the　concentration　inversion　function　to　disclose　the　displacement　of　the　center　of　the　laser　spot　at　different　heights　in　the　gas　jet.　The　spot　images　of　the　laser　beam　passing　through　the　gas　jet　at　three　vertical　heights　z　=　10d,　20d,　30d,　and　different　radial　positions　are　obtained.　The　radial　spatial　asymmetry　of　the　gas　jet　is　also　found　in　the　experiment.　Finally,　the　calculated　concentration　distribution　curve　and　the　fluent　simulation　curve,　it　is　found　that　the　two　results　are　very　similar.　Our　findings　show　that　the　error　between　the　concentration　distribution　of　this　method　and　the　simulated　concentration　distribution　reaches　2.43%.　©　2022　Hydrogen　Energy　Publications　LLC