The utility model discloses a voltage detecting device and deicing device for overhead earth wire mechanical shock de -icer, including voltage display alarm device and the power source of setting on voltage display alarm device, voltage display alarm device includes transistor T, bee calling organ K, voltage display Z, resistance R1 and resistance R2, transistor T's base b connecting resistance R1 and resistance R2 link, voltage input end U0 is connected simultaneously to resistance R1 other end link, the projecting pole e who connects voltage input end U1 and transistor T is simultaneously connected to the resistance R2 other end, transistor T's collecting electrode c connects bee calling organ one end, voltage input end U0 is connected to the bee calling organ other end, voltage display still connects in parallel between voltage input end U0 and voltage input end U1, voltage input end U0 and voltage input end U1 all connect power source. By adopting the above structure, the utility model, the controllability and the reliability of the assurance work of opening ice improve staff's work efficiency.