Reliability　analysis　of　bridges　is　essential　for　the　design　of　civil　engineering　structures.　The　classical　methods,　such　as　Monte　Carlo　Simulation　(MCS)　and　subset　simulation　techniques,　may　provide　accurate　results.　However,　since　the　finite　element　model　of　the　large-scale　civil　engineering　structures　usually　consists　of　a　large　number　of　degrees　of　freedom,　structural　reliability　analysis　of　such　structures　is　time-consuming　and　computational　intensive,　which　may　restrict　the　use　of　these　methods.　This　paper　proposes　a　novel　method　for　the　reliability　analysis　of　bridge　under　different　types　of　loads　by　combining　Polynomial　Chaos　(PC)　and　subset　simulation　techniques.　The　surrogate　model　of　the　limit　state　function　is　approximated　by　using　the　PC　expansion,　in　which　the　PC　coefficients　are　obtained　from　the　least-squares　method.　The　subset　simulation　with　a　PC-based　surrogate　model　is　then　used　to　estimate　the　rare　failure　probability.　Reliability　analyses　of　bridge　structures　under　different　loading　types,　that　is,　static　load,　dynamic　moving　load,　and　seismic　load　are　performed.　Studies　by　using　the　MCS　method　and　the　classical　subset　simulation　are　also　conducted,　and　the　results　from　the　proposed　approach　are　compared　with　those　from　MCS　and　subset　simulation　to　demonstrate　the　accuracy　and　efficiency　of　the　proposed　method.　©　2023　The　Authors.　Earthquake　Engineering　and　Resilience　published　by　Tianjin　University　and　John　Wiley　&　Sons　Australia,　Ltd.