Double-sided FSW technology with dynamic support was applied in the large diameter spiral tube of aluminum alloy for the first time in this paper,the spiral tube with diameter of 900 mm and length of 20 m was successfully produced in one time,and the welding process was stable and reliable. Dye penetration inspection,ultrasonic inspection and X-ray inspection were carried out on the whole weld of spiral tube,and X-ray inspection were carried out on the partial weld of spiral tube,and the weld thinning and tube roundness were measured. The results showed that no defects were found in the three kinds of inspection,and the weld thinning was strictly controlled in the range of 0.3 ～0.5 mm and the tube roundness was 0.15 ～2 mm. The successful application of double-sided FSW technology with dynamic support in the production of large diameter aluminum alloy spiral tube will effectively avoid low efficiency,metallurgical defects,large deformation,environmental pollution of traditional welding technology. This project will truly realize the welding production of large diameter aluminum alloy spiral tube with high efficiency,high yield,high quality,and green environmental protection.