结合已开工建设的青岛地铁一期工程（3号线）的工程实际，针对青岛城市特色及地铁工程特点，对地铁线路埋深进行了分析总结思考。依据不同的规范及理论公式进行地铁隧道覆跨比推算，并进行横向对比分析，得到一个相对合理的量化理论值。针对3号线工程实施过程中出现的技术及非技术难题，从施工技术、环境影响、工程经济、功能需求和出入口的设置等角度对花岗岩地层中地铁隧道的埋深进行了较为深入的定性分析。采用定量和定性分析相结合手段，充分利用青岛地铁既有硬质花岗岩自身良好的自稳条件，从降低施工难度，减少对周边环境影响，节约工程投资等角度出发，建议青岛市后续地铁线路宜选择适当埋深、暗挖方法，地铁隧道覆跨比选择对于车站隧道采用0.9～1.1，区间隧道采用0.5～0.6比较适合青岛地区隧道工程。

Comments are made on the cover thickness of Metro works, with No. 3 line of Qingdao Metro as an example. The coverspan ratio of Metro tunnels is calculated according to different codes and theories and a rational quantitative theoretical value is obtained by means of comparison and analysis. Qualitative analysis is made on the cover thickness of Metro tunnels located in granite strata in terms of construction technology, environmental influence, engineering economical efficiency, functional requirements and entrance/exit arrangement. Recommendations are made on the subsequent construction of other lines of Qingdao Metro, so as to overcome the construction difficulties, minimize the influence on the surrounding environment and reduce the cost.