Abstract: Digital detonator's blasting was totally adopted in a Shallow Covered tunnel to be drilled，but blind cannon occured frequently.According to the digital blasting cap's internal structure principle，blasting cap's tensile strength，the speed of explosive residue theory and other aspects， the various reasons of blind cannon were analyzed with shallow covered tunnel blasting by detailed computing.In view of these problems，finally some practical suggestions were given to prevent the blind cannon by adjusting the blasting equipment，the short-delay time，the blasting network connection，the charging structure，and the quality of blast hole filling.And these measures were effective.

Key words: Tunnel blasting, Blind cannon, Digital detonator