Abstract: The new quenching forming process of aluminium alloy L section bar was taken as the research object, and the residual stress distribution under different process parameters was obtained by restoring the new quenching forming process by using Deform software.The residual stress distribution was assigned to the nCode software, and the fatigue life under different process parameters was predicted based on the nominal stress method, and the new quenching forming process parameters under the highest fatigue performance were determined:solution treatment at 470 ℃and heat preservation for 40 min, quenching at 20 ℃water, stamping speed of 60 mm/s, first-stage aging of 170 ℃/10 min, second-stage aging of 120 ℃/20 min, and the fatigue test verifies the accuracy of prediction, which provides important guidances for actual production.