A rotor device of an integrated starter-generator motor and a rotor working system are disclosed in the present invention. The rotor device is a monobloc cast, that is machined, to form an inseparable one-piece structure. The rotor device takes the shape of a straw hat and is provided with an external side surface of a hat top being surface (11), an external side surface of a hat brim being surface (13), an inner side surface of the hat brim being surface (12) and a surface (14) which connects the surface (11) with the surface (13). The surface (11) of the rotor device is provided with multiple through holes (1) used for fixing with a crankshaft (82). The surface (12) of the rotor device is provided with multiple threaded holes (2) used for connecting with a clutch. The threaded holes (2) pass through the surface (13) corresponding to the surface (12).