A three-channel spark igni tion techni que was developed to i ncrease the fuel lean ignition probability i n the present study. By fi xi ng the total igni tion energy, a spati all y separated and temporall y synchroni zed di scharge was performed i n thi s ignition system to i ncrease the igni tion vol ume. The di scharge performance between the mul ti-channel and si ngle-channel igni tion systems was i nvestigated i n a spheri cal bomb with di fferent pressures, discharge gaps. It shows that the igni tion probability is i ncreased and the fuel-lean igni tion limit is extend i n the mul ti-channel spark system at di fferent discharge gaps. And under conditions of smaller discharge di stances the enhancement due to the mul ti-channel spark is more signi ficant.