A　simplified　analytical　solution　is　developed　for　estimating　the　thrusts　and　bending　moments　of　the　circular　tunnel　in　half　space　under　the　obliquely　incident　SV　wave.　The　seismic　waves　impinging　on　the　tunnel　is　obtained　according　to　the　elastic　wave　motion　theory　in　half　space　firstly,　which　is　the　superposition　of　the　incident　and　reflected　SV　waves　and　reflected　P　wave.　Then,　by　considering　the　tunnel　lining　as　a　thick-wall　cylinder,　analytical　solutions　for　internal　forces　of　circular　tunnel　due　to　the　incident　and　reflected　SV　waves　and　the　reflected　P　wave　are　deduced,　which　enables　more　precise　forecasts　than　previous　analytical　solutions　by　the　thin　shell　model.　The　total　tunnel　internal　forces　are　obtained　finally　through　the　superposition　of　the　above　solutions　under　three　kinds　of　waves.　The　accuracy　of　the　proposed　analytical　solution　is　verified　by　comparing　with　the　dynamic　numerical　results.　Moreover,　the　discussion　about　the　effect　of　critical　factors　on　the　accuracy　of　the　proposed　analytical　solutions　is　conducted,　including　the　tunnel　structure　inertia,　the　seismic　wavelength,　the　lining　thickness　and　the　tunnel　depth.　These　results　demonstrate　that　the　proposed　analytical　solution　performs　well　and　can　be　adopted　to　predict　the　internal　forces　of　circular　tunnel　under　obliquely　incident　SV　wave　in　seismic　design.