Under complicated conditions, a building was partially demolished through controlled blasting. Mechanical pre-cutting was carried out before the building was collapsed by folding directional blasting. In the blasting case, a non electric initiating network was applied which was multi point detonated at different spots,had double trunk line in first stage,bunched connections and closed loops with small reseaus formed by four vents.This paper gives a description of the design and construction of the initiating network. The initiating reliability of the network is analyzed based on the reliability theoty and the maximum path principle.