The continuous annealing furnace was the key equipment for the hot-dip galvanizing line applied in UEC process， and it had crucial influence on the quality of zinc-coated products. However， in the process of production， there were always some radiation tubes that couldn't be normally ignited， or fulminatory phenomena frequently took place when lighting. These problems severely affected the efficiency， stability and safety of the continuous annealing furnace. The reasons leading to igniting failure had been detailedly analyzed in this paper and corresponding meas- ures had been come up with as well.