The invention discloses a connection unit for rod parts in a battery fixing mechanism. The connection unit comprises a square tube, compressing screws and a hinge base; and the hinge base is fixedly connected to the side wall of the square tube, the compression screws are in threaded connection to the square tube, and one end of each compression screw penetrates the side wall of the square tube and stretches into the square tube. The connection unit is simple in structure, convenient to manufacture and use and good in connection effect.