The invention provides a hole helical milling device, which comprises a frame, a main shaft system, a deviation regulating mechanism, a revolution system and an anti-winding mechanism. The main shaft system includes an electric main shaft and a milling cutter fixed to the free end of the electric main shaft, and the electric main shaft drives the miller cutter to rotate. The deviation regulating mechanism includes an inner cylinder and an outer cylinder, the inner cylinder surrounds the electric main shaft, the outer cylinder surrounds the inner cylinder, the inner circle and the outer circle of the outer cylinder are eccentrically arranged, and the inner circle and the outer circle of the inner cylinder are eccentrically arranged. The revolution system includes a driving motor, a pinion and a bull gear, the driving motor drives the pinion to drive the bull gear so as to realize revolution of the main shaft system, and an eccentric distance exists between the axial line of rotation of the milling cutter and the axial line of the revolution of the main shaft system. The device disclosed by the invention can be mounted on a mechanical arm, realizes accurate positioning of hole center and axial milling feeding by CNC (computer numerical control) during hole formation, is suitable for work occasions where a large number of series hole-diameter hole structures are rapidly manufactured.