The invention discloses an upper ultra-high-temperature ball valve. Graphite sealing is replaced by the unique valve seat and valve body sealing structure, the problem of high-temperature oxidation ofgraphite sealing is solved, and meanwhile, the problem about common springs in the ultra-high-temperature state is solved; a boss is designed ingeniously, a valve seat is fixed and pre-tightened, andthe specific pressure for sealing pre-tightening is reached; by the aid of a limiting cap designed ingeniously, the problems that a bonnet is lengthened at the high temperature and a ball is stuck due to expansion of a valve rod are solved; the problem of jamming of particles and powder is solved through purging in the closed and totally-open states of the valve; by the aid of the water cooling design of a jacket, the problem about the strength of the valve body when the temperature increases to 1,000 DEG C abnormally is solved, the safety guarantee is enhanced, and the problem of jamming dueto thermal expansion of the valve is solved.