Abstract: A highprecision detonator detonation network usually uses a surface detonator at a connection point.This detonation network is simple in construction and low in cost.However,a single detonator connection is difficult to guarantee a stable blowout under any circumstances.Taking an openpit mine as the stduy example,the singleconnection network is changed to a double network.This means that there are two surface detonator connections at each of the blast points.Double network design is inferior to single network design in terms of construction efficiency and cost,but double network is obviously better than single network in terms of bursting reliability，besides that,its safety and economic benefits are considerable.It is suggested that double network blasting design should be adopted when economic conditions permit in some mines.

Key words: High precision detonator,Double network,Reliability