The invention discloses a one-shot forming device of a steel tube grounding pile tip, and belongs to grounding pile forming devices. The one-shot forming device is characterized by further comprising a lower installation plate, a support plate, a sliding rail pressing plate, a flat cushion plate, a die sleeve, a sliding rail, a die core I, a die core II, a locating plate, a limiting plate, a steel tube seat plate, a hoop, an upper fixed plate, an upper hinged base, a connection plate I, a connection plate II, an eccentric block, a vertical face plate and a lower hinged base. The lower installation plate is fixedly installed on a base plate of a tilting-type press machine, the upper fixed plate is fixedly installed on the bottom of an upper slide of the tilting-type press machine, the connection plate I and the connection plate II drive the sliding rail, the die sleeve and the die core I to move horizontally towards the right along with vertical movement of the upper slide, the left end section of a steel tube becomes a taper along with relative extrusion of the die core I and the die core II, and therefore one-shot forming of the steel tube grounding pile tip is achieved, machining speed is high, product quality is good, and cost is low.