Ascertaining the minimum rock covers of subsea tunnel is important to reduce project cost on the conditions of subsea tunnel safety. Researching the dynamic influence of tunnel blasting construction on the cover rock mass is necessary to the minimum rock covers. The effect of subsea tunnel construction using drilling and blasting method to overlaying strata is analyzed through FLAC3D numerical simulation. The influence of different subsea tunnel level and charge weight on the interface of overlaying strata is analyzed. The blasting vibration velocity history and stress vibration history at key points and the plastic zone are gained and contrasted with the result of experimental formula; synthesizing the above analysis and considering economical and safety of subsea tunnel

we suggest that charge weight should be reduced and subsea tunnel level should be descended 2 meters.