There are air and water in the bore hole worked as interval media when the water-decked charge blasting is used in the process of tunnel excavation,and the explosion stress is more complex than single air interval.In order to select the appropriate charge structure and determine the reasonable blasting parameters to guide the site construction,taking Wenquan tunnel blasting excavation as an example,the numerical simulation method is used to simulate and analyze the blasting stress of the peripheral hole with water-decked charge,then the appropriate charge structure is selected for parameter optimization,and finally verified by the field test.The results show that in the case of the same amount of charge,the peripheral hole with water-decked charge blasting can transfer the explosion energy to the hole wall more evenly,and the surrounding rock around the hole and the rock above the holes is damaged smaller than the air-decked charge blasting,which means that the same blasting effect can be achieved,and the powder factor can be reduced by using the water-decked charge blasting.It is suitable to use 0.9 kg charge with three cartridges,0.5 m water at the bottom of the hole,0.8 m water at the mouth of the hole,and 0.3 m cartridge interval when the peripheral hole with water-decked charging structure.