Taking　the　uncertainties　in　the　high-speed　train　load,　environment　actions,　structural　resistance,　and　material　properties　into　consideration,　the　performance　function　of　CRTS　II　track　slab　for　the　horizontal　flexural　strength　is　essentially　a　stochastic　process,　which　may　be　nonstationary　and　non-Gaussian　due　to　the　nonnormal　random　variables　and　process.　In　the　present　paper,　based　on　the　fourth-moment　transformation,　a　time-dependent　reliability　assessment　method　for　nonstationary　and　non-Gaussian　process　is　developed.　In　this　method,　the　nonstationary　and　non-Gaussian　process　is　firstly　transformed　as　a　standard　Gaussian　process,　and　then　the　time-dependent　failure　probability　is　evaluated　based　on　the　transformed　Gaussian　process　and　the　cumulative　distribution　function　of　the　bivariate　standard　normal　distribution.　Next,　the　time-dependent　reliability　index　of　the　CRTS　II　track　slab　for　the　horizontal　flexural　strength　is　determined　using　the　developed　time-dependent　reliability　assessment　method.　The　results　show　that　the　CRTS　II　track　slab　will　not　be　damaged　by　the　horizontal　bending　in　the　service　lifetime.　©　2022　ISRERM　Organizers.　Published　by　Research　Publishing,　Singapore.