Introduces the composition design of high-speed flux CHF105 GX for pipeline steel,welding metal alloy system analysis,highspeed welding process characteristics,etc. Through component control,alkalinity adjustment and selection of suitable welding speci-fications,and X90,X100 special supporting pipeline welding wire,the welding test of double wire and triple wire is carried out,and the process evaluation test is carried out in the corresponding steel pope factory. The results show that the welding process is good,the weld surface is smooth,and the weld has no bite edge and pressure pit under the conditions of 160 cm/min and 180 cm/min welding speed.After welding,the performance test is carried out. The mechanical properties of the weld metal are good. The impact work at-10℃ is above 100 J,and the average impact work at-20 ℃ is above 90 J. Weld quality,bending,hardness and other indicators meet the same level and API 5 L pipeline steel high strength and toughness standards.