The invention relates to a manufacturing method of a thermal cycling test device of a turbine generator stator bar. The test device comprises a heating system, a refrigerating system, a control cabinet and a test box, and heating and cooling processes for a test bar can be automatically finished by a computer (PLC) control unit under an unattended condition. The test device is used for heating in a mode of conducting heavy current in a copper conductor, and is used for forcibly cooling the bar in a mode of forcibly ventilating and cooling externally. The device has a linear heating and cooling curve, ensures that the temperature rises and falls at uniform speed, and finishes the thermal cycling process within the specified time. The invention can be used for carrying out the thermal cycling test for the turbine generator stator bar so as to examine the capacity of resisting inner shear stress of various insulation structures.