The utility model relates to a step voltage detection alarm of transformer substation device, its characterized in that includes U type metal rod, the voltage detecting horn be electrically connected with U type metal rod, integrated with voltage display module on the voltage detecting horn. The utility model discloses the beneficial effect who has: possessing alarming function's on the premise of, increasing the display function, the suggestion of many means arouses staff's attention as far as possible, avoids participation work under the condition of insulating boot electric leakage, improves staff operational safety.