The invention provides an adjustable voltage detection and live display device for over-voltage protection. The device comprises a metal plate, a metal pin, a detection resistor and a detection loop, wherein the metal pin is perpendicular to the metal plate and a gap is remained between the metal plate and the metal plate; the root part of the metal pin is connected with one end of the detection resistor through a connecting line; the other end of the detection resistor is grounded; the detection loop is connected in parallel to the two ends of the detection resistor through a connecting line. The adjustable voltage detection and live display device for over-voltage protection has the advantage of simple and reliable structure, has an adjustable function, and can be used for measuring voltage, live display and over-voltage protection. Prototype experiments prove the effectiveness of the mechanism. The device can be applied to voltage measurement, live display and over-voltage protection.