The aircraft weather modification in largescale stratiform clouds and mixture clouds in North China is one of the important ways to relieve droughts and forest fires and improve the natural environment. The selfdeveloped L-1 Seeding System of Airborne Towed Flame with Multiple Warheads and 19 Pipes can meet the needs of precipitation enhancement operations. The system consists of the multiple warhead ammunition body, AgI catalyst, and launching and power control units. According to the experiments and primary application, the system shows obvious features of stable, easy to operate, and 100% launch rate. The nucleus rate is high up to above 1015 kg AgI at －8 ℃ and the 90% nucleus can be activated in 5 minutes after getting into clouds. The launcher can carry 760 flares so as to seed for 4 hours ceaselessly and can shoot backward. The Long B2 flame seeding system used presently has just 90% launch rate, and the launcher can carries only 200 flares, operating for only 1.5 hours and shoots laterally with less flexibility, so mechanical failures occurs frequently.