Electric spark machining method and machining system for internal key groove of rudder shaft hole

The invention discloses an electric spark machining method and system for an inner key groove of a rudder shaft hole, and belongs to the technical field of electro-hydraulic steering engine machining. The problems of low yield, low processing efficiency, high processing cost and the like of the rudder shaft are solved. The electric spark machining method comprises a primary machining procedure and a rounding procedure. In the primary machining procedure, a first electrode is arranged on electric spark machining equipment, and the electric spark machining equipment controls the first electrode to machine the key groove in the rudder shaft hole according to preset electric parameters. And in the rounding process, the electric spark machining equipment is provided with a second electrode, and the electric spark machining equipment controls the second electrode to conduct rounding treatment on the key groove according to preset electric parameters. The preset electrical parameters comprise a preset pulse width, a