The invention discloses a watertight reference electrode, comprising a watertight electrode and a watertight cover; in the watertight electrode, an electrode body and a water permeable protective net are arranged inside a protective sleeve, one end of the electrode body is opposite to the water permeable protective net, and the electrode body The other end of the cable is connected with a cable, the cable extends to the outside of the protective sleeve, the first sealing filler is filled in the gap between the protective sleeve and the electrode body, and the setting position of the first sealing filler matches the connection position of the electrode body and the cable; the watertight cover is filled inside There is a second packing, and the electrode stuffing box base is installed with a watertight electrode, the gap between the electrode stuffing box base and the watertight electrode is filled with a third packing, the cable stuffing box base is installed with a cable, and the cable stuffing box base and the cable are installed. The gap between them is filled with a fourth sealing packing, and the cable extends from the inside of the watertight cover through the base of the cable stuffing box to the outside; therefore, this solution realizes four layers of waterproof protection, and completely solves the problem of poor watertight performance of the existing watertight reference electrode.