The invention provides a bi-rotary milling head integrated with a pneumatic assistance chip removal device. The bi-rotary milling head comprises an A-axis movement device, a C-axis movement device, a rotary cutter device and the pneumatic assistance chip removal device, wherein the A-axis movement device at least comprises an A-axis driving unit, an A-axis shield and an electric spindle installation base; the C-axis movement device at least comprises a C-axis driving unit, a C-axis bearing pedestal, a rotating shaft and a rotating main body; the rotary cutter device at least comprises an electric spindle, a cutter and a cooling pipeline; the pneumatic assistance chip removal device at least comprises an air blowing mouth and a high-pressure air pipeline. According to the bi-rotary milling head, because all electrical wires and the cooling pipeline are concealed, the rotation angle of the machining cutter cannot be limited, and casting moulds, which have large structural sizes and complex cavity curved surfaces and are difficult to form, of large complex castings can be produced. In addition, the pneumatic assistance chip removal device is designed, and therefore external waste chips can be effectively prevented from invading, the rotating cutter is cleaned, and machining precision of machining equipment is guaranteed to a certain degree.