The present invention relates to a method for manufacturing a nonmagnetic water-cooled microwave ablation needle. The manufacturing method is designed for a microwave ablation needle of a nonmagnetic material and has a proper process procedure, favorable assembly quality, and high production efficiency. The produced nonmagnetic water-cooled microwave ablation needle is applicable to microwave tumor ablation surgery in a nuclear magnetic resonance imaging environment, and helps a doctor in charge to clearly determine a position of a tumor, improve piercing precision, have preferable control on a whole surgery process, improve a success rate of the surgery, reduce damage on surrounding normal tissues as much as possible on the premise of effectively inactivating the tumor, alleviate pain of a patient, and shorten a recovery cycle.