Broaching method of wheel disc of heavy combustion gas turbine

The invention relates to a broaching method, in particular to a broaching method of a wheel disc of a heavy combustion gas turbine, and aims to solve the problems that a mortise of a turbine disk of a rotor of the conventional heavy combustion gas turbine has a complex molded line and a high demand for precision, and the conventional process and detection means hardly realize broaching process and detection of the mortise. The method comprises the steps as follows: six broaches are mounted in each of the first five broach boxes, and seven broaches are mounted in the sixth broach box; the wheel disc is hoisted, so that a bolt hole on the wheel disc falls on an adaptive ring on the upper surface of a base clamping ring of a clamp through a positioning pin and a compression bolt on the clamp; and the mortise on the edge of the wheel disc is broached through the six broaches in the first broach box, then the second broach box is used instead to broach the mortise on the edge of the wheel disc, and the operation circulates in such a way until the six broach box finishes broaching the mortise on the edge of the wheel disc. The invention is used for broaching the wheel disc of the heavy combustion gas turbine.