The invention provides a full automatic inner bore polishing machine, comprising a fixing device and polishing devices arranged at two ends of the fixing device; the four corners on the bottom of the fixing device are provided a plurality of groups of height regulating mechanisms; the fixing device is provided with at least one pair of steel pipe lifting mechanisms; the steel pipe lifting mechanisms are provided with transversely sliding feeding frames; each polishing device is provided with a polishing component, a fixing type guide mechanism and a moving type guide mechanism; each polishing shaft penetrates between the corresponding fixing type guide mechanism and corresponding moving type guide mechanism; and each fixing type guide mechanism is provided with a flexible connector, and the flexible connectors are connected to the corresponding moving type guide mechanisms and polishing components respectively. Compared with the existing polishing device, the full automatic inner bore polishing machine has the advantages that the polishing stability is high, the vibration is small, the distance between the polishing shaft and a clamp can be quickly regulated accurately, bending of the polishing shaft is avoided, the polishing machine is suitable for a large range of apertures, wall thicknesses and standards of tubular products, the tubular products can be carried without labor, and the operation intensity of workers is greatly reduced.