The invention provides a high-temperature metal hard seal ball valve for granular media. The high-temperature metal hard seal ball valve comprises a valve body, a ball body, a valve rod, a valve seat and a bottom cover, wherein the ball body is arranged in a cavity in the valve body, the valve rod connected with the ball body extends out of the valve body through a center through hole at the upper part of the valve body, the bottom cover is positioned at the bottom of the valve body and comprises a bottom cover baseplate and a bottom cover shaft, the bottom cover baseplate is movably connected with the valve body, the bottom cover shaft penetrates through a through hole at the lower part of the valve body and is connected with the ball body in the cavity of the valve body, the ball body and the valve seat are made of metal materials, the valve seat is mounted in the valve body and on the inner wall which is in contact with the ball body, a spring seat is arranged on the outer side of the valve seat, a disc spring is mounted in a groove between the spring seat and the valve seat, a pressure ring is arranged on the outer side of the spring seat, the pressure ring is fixedly mounted on the spring seat through a screw, a pendant collet for playing a sealing role is arranged in the contact position of the spring seat, the pressure ring and the valve body, an O ring is arranged in the groove between the valve seat and the valve body, and the O ring is made of fluorine rubber.