The invention discloses a dynamic monitoring device and method for tilt of a high-voltage electric tower. The device comprises a loading panel, a self-rotating mechanism and a measurement tank, wherein the measurement tank comprises a tank body, a dial, a tilt measurement mechanism and a tilt warning mechanism, the tilt measurement mechanism comprises a rotating shaft, a rotating shaft gear, a rotating rod gear and a swing rod, one end, far away from a swing ball, of the swing rod is connected with a rotating rod through a connecting rod, and the connecting rod is in spline fit with the rotating rod; and the tilt warning mechanism comprises a short rod, a rotating disc with an electric groove and a metal pulley, the metal pulley is provided with a GPS emitter, and a push rod is arranged on the rotating shaft. The method comprises the following steps: (1) determining the length of a short rod, and setting a tilt angle warning value of the high-voltage electric tower; (2) stabilizing the measurement tank; (3) carrying out tilt measurement on the high-voltage electric tower; and (4) converting a display angle of the dial into an actual tilt angle of the high-voltage electric tower. According to the dynamic monitoring device and the dynamic monitoring method, the sinking tilt of the high-voltage electric tower can be automatically detected in real time, the timely remote dynamic warning monitoring is realized, and the tilt measurement is not interfered by an electromagnetic field of the high-voltage electric tower.