The invention discloses an overload protection type combined synchronous belt wheel for synchronous belt transmission. An upper guide cylinder, a lower guide cylinder, a left guide cylinder and a right guide cylinder are machined in a synchronous belt wheel hub in the radial direction; a conical hole is formed in the synchronous belt wheel hub in the axial center line direction; an upper ejectingcolumn is mounted in the upper guide cylinder; a lower ejecting column is mounted in the lower guide cylinder; a left ejecting column is mounted in the left guide cylinder; a right ejecting column ismounted in the right guide cylinder; friction plates are welded at the top end of the upper ejecting column, the bottom end of the lower ejecting column, the left end of the left ejecting column and the right end of the right ejecting column; a synchronous belt wheel tooth sleeve sleeves the synchronous belt wheel hub; the driving of the synchronous belt wheel tooth sleeve is realized through friction force between the inner wall of the synchronous belt wheel tooth sleeve and the friction plates; an ejecting cone is machined on a synchronous belt wheel driving shaft; and the taper of the ejecting cone is equal to the taper of the conical hole in the synchronous belt wheel hub. The overload protection type combined synchronous belt wheel for synchronous belt transmission is scientific and reasonable in design, simple in structure and convenient to use.