The invention relates to an electrohydraulic prostate tissue treatment probe, which comprises a probe pipe body, wherein a drainage channel, a water-injection channel, a gas-injection channel and a cathode channel are arranged in the probe pipe body along the axial direction; the front end of the probe pipe body is a guiding head; a positioning balloon is arranged behind the guiding head; an external cathode electrode is tightly wound on the probe pipe body on the rear side of the positioning balloon; a leading-out end is connected with a cathode plug through the cathode channel; an external anode electrode is arranged between the positioning balloon and the cathode electrode, is wound by one circle at least, and is kept in a certain interval from the cathode electrode; and the leading-out end is connected with an anode plug through the drainage channel. The probe has the advantages that the probe is large in treatment range, safe, reliable, free from damage to non-target organs, insusceptible to cause relapse and insusceptible to produce fibrous plaque hyperplasia and cicatricial stenosis, reduces cost, can effectively eliminate the hidden trouble of cross infection, enables patients to have good tolerance and slight adverse reaction, and is particularly suitable to treat elderly high-risk patients who suffer from prostatic hyperplasia and cannot tolerate operations and anesthesia.