Based　on　the　mirror　image　method　and　superposition　principle,　an　analytical　model　of　seepage　field　for　symmetrical　underwater　tunnels　is　proposed.　The　condition　is　assumed　as　two-dimensional　steady　water　inflow　into　symmetrical　and　horizontal　underwater　tunnels　in　a　fully　saturated,　homogeneous,　isotropic,　and　semi-infinite　aquifer.　Analytical　solutions　of　pore　water　distribution　and　water　inflow　into　tunnels　are　obtained.　Two　different　boundary　conditions　at　the　perimeter　of　symmetrical　tunnels　are　considered,　constant　total　hydraulic　head　and　constant　water　pressure.　Taking　the　subsea　tunnels　of　Xiamen　Xiang＇an　in　China　as　an　example,　comparisons　between　analytical　solutions　and　numerical　solutions　are　analyzed　in　the　case　of　zero　water　pressure　at　the　perimeter　of　symmetrical　tunnels.　The　results　show　that　the　analytical　solutions　for　pore　pressure　distribution　and　water　inflow　match　well　with　the　numerical　solutions　and　that　the　relative　deviations　are　all　in　an　acceptable　range.　The　solutions　derived　from　the　analytical　model　in　this　paper　can　analyze　the　steady　seepage　field　of　symmetrical　underwater　tunnels　accurately　and　reasonably.