The invention discloses an equipotential field protection device, which comprises a potential protection module, a current sensor and an alarm module, wherein the potential protection module comprisestwo insulating protective layers, a conductive grid layer is clamped between the two insulating protective layers; the conductive grid layer is provided with at least two symmetrically arranged electrode leading-out ends, the electrode leading-out ends are communicated with a grounding wire to form a loop, the current sensor is arranged between the conductive grid layer and the electrode leading-out ends, and the current sensor is electrically connected with the alarm module. When a large current accident occurs, the step voltage is generated, the current at the electrode leading-out end is induced inside the conductive grid layer through a larger current and the current sensor, the current is converted into a voltage value, the alarm module is driven to generate early warning, and the formed step voltage is subjected to the early warning function, so that an operator can know the danger, guide the operator to pay attention as soon as possible, and concentrate on checking the potential safety hazard, thereby reducing the personal harm.