Two-way flow head spin ball valve is the superior combination of ball valve sealing performance and the advantages of butterfly valve structure performance research and development, its namely with ball valve sealing, two-way adjustable, long service life and practical advantages, and have the butterfly valve structure of the advantages of small volume, light weight. The essence of the hemisphere of an eccentric structure of butterfly valve. Sealing principle combined with the front end of the fixed ball valve sealing force with eccentric butterfly valve seal, so as to realize the high and low voltage two-way cut off. In the seal of the two seal surface can be used according to the different hardness space plasma spraying, the etheric laser sputtering, vacuum after pile of advanced technology such as the protection permeating martensitic stainless steel, austenite stainless steel, hard alloy, metal, ceramics, functionally gradient materials such as synthetic diamond. Automatically to align the center (adaptive), automatic wear, the more distance compensation to seal high pressure automatically, instantaneous closing, no friction between instantly open the seal, when open the valve core projection swelling and move forward, short structure, small volume.