The invention discloses a self-suction cup which comprises a cup body and a cap lid. The cap lid is arranged at the upper end of the cup body, a tea placement groove is formed in the upper side of the cap lid, an annular frame is arranged at the inner upper portion of the cup body, a water purifying unit is arranged on the annular frame, a fixing frame is arranged at the inner lower portion of the cup body, a positive
electrode and a negative
electrode are arranged inside the fixing frame, a water-permeability membrane is arranged between the positive
electrode and the negative electrode, a groove is formed in the lower end of the cup body, a connecting rod is arranged in the inner middle portion of the groove, a fixing unit is arranged at the lower end of the connecting rod and comprises a shell and a suction disc, a cavity is formed in the shell, a movable plate is arranged inside the cavity, the lower end of the connecting rod is connected with the upper side of the movable plate, a venting
pipe is arranged on the right side of the shell, the lower end of the venting
pipe is communicated with the suction disc, and the other end of the venting
pipe is communicated with the upper portion of the cavity. The self-suction cup is simple in structure, convenient in use, stable in placement, convenient in carry and capable of improving drinking
water quality.