The utility model discloses a water cooling microwave ablation aciculiform antenna with an alcohol injection structure, and belongs to a medical instrument used for tumor ablation treatment. The aciculiform antenna comprises a radiator, wherein an aciculiform radiator cover is installed on the radiator, the radiator is installed at the front end of a needle bar, a radio frequency coaxial connector is further installed at the rear end of the needle bar, a coaxial cable is further arranged in the needle bar, a water inlet channel and a water outlet channel are further formed in the needle bar, the water outlet channel is further communicated with a water outlet structural cavity in the tail end of the needle bar, an injection channel is further formed in the needle bar, the rear end of the injection channel is communicated with a water fetching pipe, the front end of the injection channel extends to the front end of the needle bar, and the front end of the injection channel is communicated with water outlet holes in the rear end of the radiator. Because the mode that saline solutions are injected at the same time through capillary tubes is adopted in the microwave ablation process, the probability that the front end of a needle bar is carbonized at a high temperature due to overhigh power is reduced, the ablation range is broadened, and the curative effect of ablation is effectively improved; meanwhile, the water cooling microwave ablation aciculiform antenna with the alcohol injection structure is simple in structure, suitable for industrial production and easy to popularize.